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rapaljer answered: 4664 problems
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Numbers_Word_Problems/682532: Find the value of 327 in the mod 7 system.
1 solutions

Answer 423222 by rapaljer(4667) About Me  on 2012-11-18 23:21:06 (Show Source):
You can put this solution on YOUR website!
Divide by 7, and see what the remainder is.

327 divided by 7 gives you 46 with a remainder of 5, right?? so 327(mod 7) = 5.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Probability-and-statistics/682541: the probability that her age will fall between 55 and 60 years is____
the probability that her age will fall between 47 and 53 years is___
the probability that her age will be less than 35 years is____
the probability that her age will exceed 41 years is___
1 solutions

Answer 423219 by rapaljer(4667) About Me  on 2012-11-18 23:15:07 (Show Source):
You can put this solution on YOUR website!
Were you given the mean and standard deviation of the population???

Dr. Robert J. Rapalje, Retired


Polynomials-and-rational-expressions/682468: factor completely:
X^4-2X^2-16X +32 = 0

1 solutions

Answer 423215 by rapaljer(4667) About Me  on 2012-11-18 22:58:56 (Show Source):
You can put this solution on YOUR website!
I LOVE factoring, but I think you copied this one wrong!!! If I am wrong, please send me an Email (or a Thank You note!), and I'll try again for you.

This is a "Factoring by Grouping" problem where you must group the first two and the second two together!

x^3 - 2x^2 - 16x + 32 = 0

x^2(x-2) - 16(x-2) = 0

Now, take out the common factor of (x-2).
(x-2) (x^2 - 16) = 0

Now, factor the difference of squares:
(X-2)(x-4)(x+4) = 0

Finally, this is an EQUATION, so solve the equation by setting each factor equal to zero:
x= 2, x=4, x=-4

I have a LOT of explanations, examples, and FULL COLOR solutions to problems like this on my own website. I even have VIDEOS of me teaching this type of factoring in my younger days before I retired and my hair was still dark!! This is a GREAT chapter if you get a good explanation of it--not nearly as hard as your textbook is making it.

My website is all FREE with NO ADVERTISING, and I'm not selling anything! I just want to make this as easy as I can for you.

To see my website go to www.mathinlivingcolor.com, named after my theme "Math in Living Color." Look for a single link near the bottom of this page that will take you to my Homepage. Once on my Homepage, look for "Basic, Intermediate and College Algebra: One Step at a Time", and select "Basic Algebra". Look in "Chapter 2" for the appropriate topics!

As for the videos, look for the link on my Homepage called "Rapalje Videos in Living Color", and choose either Basic or Intermediate Algebra. Choose the videos that have to do with Factoring.

If you have questions on other topics, just send me an Email! I'll be glad to help you find the right page on my website. I hope you like my website and that you will recommend it to family and friends! Remember, my goal is to make math EASIER than your own textbook is making it, and it's ALL FREE!!!


Dr. Robert J. Rapalje, Retired
Seminole State College of Florida

www.mathinlivingcolor.com.


Miscellaneous_Word_Problems/682506: Hi. Can you help me solve this? I'm stuck.
How many teams are in a league that schedules 45 games in such a way that each team plays every other team only once?
Thanks.
1 solutions

Answer 423214 by rapaljer(4667) About Me  on 2012-11-18 22:15:35 (Show Source):
You can put this solution on YOUR website!
Let x = number of teams in the league. Since each game includes 2 teams, you are looking for a COMBINATION problem, C(x,2) = 45.

In other words, +%28x%2F2%29%2A%28%28x-1%29%2F1%29+=+45

x%2A%28x-1%29+=+90

Now, if you are an algebra student, you should multiply out the left side to obtain x^2 - x = 90, and solve the quadratic equation.
x^2 - x - 90 = 0
(x-10)(x+9)=0
x= 10 or x=-9, reject the negative answer. There are 10 teams in the league.

If you are a statistics student, you should ask yourself, what number times one more that the number would give you a product of 90. Probably pretty obvious that the numbers would be 9 and 10.

To analyze the answer, what you have is 10 teams in the league, and each team has 9 opponents. Lest you think this gives you 90 games, remember that Team A playing Team B is the same as Team B playing Team A, so you have to divide by 2 in order to eliminate the duplication of games.


Dr. Robert J. Rapalje, Retired
Seminole State College of Florida

P.S. Check out my website for full color explanations and lots of practice tests with detailed solutions for all levels of math at www.mathinlivingcolor.com.


Exponents-negative-and-fractional/682500: Rational exponents: Negative exponents and fractional bases
What is the answer without exponents?
(1/8)2/3=?
125 -2/3=??

1 solutions

Answer 423213 by rapaljer(4667) About Me  on 2012-11-18 22:03:04 (Show Source):
You can put this solution on YOUR website!
These are NOT nearly as hard as they look!!

%281%2F8%29%5E%282%2F3%29+ means to take the CUBE ROOT of (1/8), which is 1/2.
Then RAISE to the 2 power, so the answer is +%281%2F2%29%5E2=1%2F4

125%5E%28-2%2F3%29 means to take the CUBE ROOT of 125, which is 5.
Then, raise to the -2 power, so the answer is 5%5E-2=+1%2F25.

For a more complete explanation of this topic in my own words, please see my own website, which is easy to find by using the link www.mathinlivingcolor.com. Click on the link near the bottom of this page, and go to my Homepage. Once on my homepage click on the link "Basic, Intermediate, and College Algebra: One Step at a Time". Select "Intermediate Algebra", and look in Chapter 3, Section 3.05 Fractional Exponents." You probably will like my FREE explanations with many solutions in COLOR on the corresponding "Math in Living Color" pages.

I hope you like the website and that you will recommend it to friends and family.


Dr. Robert J. Rapalje, Retired
Seminole State College of Florida

www.mathinlivingcolor.com.


Rate-of-work-word-problems/682497: A hose takes 15 minutes to fill a swimming pool and the drain empties the pool in 20 minutes. How long will it take to fill the pool if the drain is left open?
I thought my teacher said the answer was 80 minutes but I only could figure out 1/15-1/20=1/60 making it 60 minutes. Can you explain my mistake please?
1 solutions

Answer 423209 by rapaljer(4667) About Me  on 2012-11-18 21:52:10 (Show Source):
You can put this solution on YOUR website!
I'm sorry but I can't see how it could be 80 minutes, and I don't see anything wrong with your equation.

Let x = time it takes for the pool to fill given that the drain is open and the hose is turned on.

1/15 = amount of the pool filled in 1 minute with hose only and drain closed.
1/20 = amount of the pool emptied in 1 minute with the drain open and no hose.

1%2F15+-+1%2F20+=+1%2Fx, solve for x. The LCD is 60x, and the answer is x=60.

Why don't you re-post the problem. Maybe someone else has another idea on this one.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida

P.S. Check out my website for full color explanations and lots of practice tests with detailed solutions for all levels of math at www.mathinlivingcolor.com.


Rational-functions/682492: How to rewrite g(x) to look like f(x) and f(x) to look like g(x)?
g(x)=0.25^(1-x)
f(x)= 4^(x-1)
1 solutions

Answer 423204 by rapaljer(4667) About Me  on 2012-11-18 21:37:58 (Show Source):
You can put this solution on YOUR website!
g%28x%29+=+0.25%5E%281-x%29
g%28x%29+=+%281%2F4%29%5E%281-x%29
g%28x%29+=+%284%5E%28-1%29%29%5E%281-x%29
g%28x%29+=+%284%5E%28-1%2A%281-x%29%29%29+
g%28x%29+=+4%5E%28x-1%29++=+f%28x%29+

Converting f(x) to g(x) will be a similar process, somewhat in reverse!

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida

P.S. Check out my website for full color explanations and lots of practice tests with detailed solutions for all levels of math at www.mathinlivingcolor.com.


Equations/632843: solve y^2+14y=32 by completing the square,..thnks
1 solutions

Answer 398511 by rapaljer(4667) About Me  on 2012-07-29 08:26:15 (Show Source):
You can put this solution on YOUR website!
Take HALF of the coefficient of y, which is 7, and SQUARE it to get 49. Add this to each side of the equation:

y^2 + 14y + 49 = 32 + 49
(y+7)^2 = 81

Take the square root of each side:
%28y%2B7%29+=+0+%2B-+9
y=-7+%2B-+9

Calculate each value:
y=-7 +9 =2

y=-7-9 = -16

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Functions/632367: f(x) = x-8/x-7 find the domain of the rational function

1 solutions

Answer 398242 by rapaljer(4667) About Me  on 2012-07-27 09:46:57 (Show Source):
You can put this solution on YOUR website!
DOMAIN is one of my favorite topics! It's not nearly as hard as it looks. You just have to know what is NOT allowed in math, and in this case, what is not allowed is DIVISION BY ZERO. Anytime you have a denominator, you must NEVER divide by zero, so in this case, the denominator of x-7 must NOT equal zero, so x cannot equal 7. Domain is ALL VALUES OF X except 7.

For additional explanation on DOMAIN, please see my own website. Look for the easy-to-remember and easy-to-spell link www.mathinlivingcolor.com. At the bottom of this page is a link that takes you to my Homepage. Near the top of the Homepage, look for the link: "Basic, Intermediate, and College Algebra: One Step at a Time." Choose "Intermediate Algebra" and look in Chapter 1, or Choose "College Algebra" and look in Chapter 2.

In addition, there are VIDEOS of me teaching these lessons before I retired. The videos can be found by looking on my Homepage for the link "Rapalje Videos in Living Color." Choose either Intermediate or College Algebra and look for the video called "Functions, Domain and Range."

You will probably like my explanations, especially the PRICE of them!! They are ALL FREE!! My own students before my retirement thought my books were easier to understand than the traditional books, and many of the solutions are given IN COLOR in the attached "Math in Living Color" pages.

Most any algebra topic you need is probably there somewhere. If you need help finding the right page on the website, please send me an Email at rapaljer@seminolestate.edu. If you like my website, please recommend it to family and friends.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Geometry_Word_Problems/632353: If you wrap a piece of wire 8 times around a pipe and the length of the pipe is 20cm and the circumference is 6cm, what is the length of the wire?
1 solutions

Answer 398239 by rapaljer(4667) About Me  on 2012-07-27 09:36:49 (Show Source):
You can put this solution on YOUR website!
When I first read this problem, I'm afraid that I interpreted incorrectly. This is actually supposed to be a wire wrapped AROUND and UP the pipe in a spiral manner (this is called a HELIX in case you want to look into this for additional explanation),

Begin by picturing a vine or a wire wrapped 6 times around a tree trunk that is 20 feet high and whose circumference is 8 feet. If the circumference is 8 feet, then the DIAMETER of the trunk of the tree is 8/pi. Now, suppose you cut the tree off at the base, and lay the tree flat on the ground, and UNWRAP the vine or wire by fastening the vine at the top of the tree and rolling the tree on the ground. When the vine is completely unwrapped, the vine will form the hypotenuse of a right triangle, where the first leg (the height of the triangle!) is the original position of the tree on the ground, which is 20 feet, and the second leg (the base of the triangle!) is the path traced out by the base of tree as it was rolled to unwind the vine. Can you picture this?

The tricky part to figure is the length of the second leg of the right triangle. Each time you rolled the tree to unwrap one complete wrapping of the vine, the tree rolls ONE circumference, which would be 8 feet. Since the vine wrapped a total of 6 times around the tree, this means that the total distance the tree rolls to completely unwrap the vine will be 6*8 feet or 48 feet.

So, picture a right triangle whose height is 20 feet and whose base is 48 feet. The total length of the vine is the hypotenuse, which is sqrt%28+20%5E2+%2B+48%5E2%29=52+feet.

Of course, change the feet to cm for this particular problem. The final answer is 52+cm.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Proportions/632362: It takes Kurt twice as long to earn $60 as it takes Paul to earn $40.What is the ratio of Kurt's pay per hour to Paul's pay per hour?
1 solutions

Answer 398237 by rapaljer(4667) About Me  on 2012-07-27 09:29:58 (Show Source):
You can put this solution on YOUR website!
Kurt earns $60/2 units of time = $30/ unit of time compared to Paul who earns $40 per unit of time.

The ratio of Kurt's pay to Paul's pay = 30/40 = 3/4.

For additional explanation on Ratio and Proportion, please see my own website. Look for the easy-to-remember and easy-to-spell link www.mathinlivingcolor.com. At the bottom of this page is a link that takes you to my Homepage. Near the top of the Homepage, look for the link: "Basic, Intermediate, and College Algebra: One Step at a Time." Choose "Basic Algebra" and look in Chapter 1, for Section 3.08.

You will probably like my explanations, especially the PRICE of them!! They are ALL FREE!! My own students before my retirement thought my books were easier to understand than the traditional books, and many of the solutions are given IN COLOR in the attached "Math in Living Color" pages.

Most any algebra topic you need is probably there somewhere. If you need help finding the right page on the website, please send me an Email at rapaljer@seminolestate.edu. If you like my website, please recommend it to family and friends.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Travel_Word_Problems/632364: Sandy and Kelvin live 385 miles apart. They each leave home at 3:00 P.M. Sandy drives 60 mph, and Kelvin drives 50 mph. At what time will they meet?

1 solutions

Answer 398236 by rapaljer(4667) About Me  on 2012-07-27 09:24:12 (Show Source):
You can put this solution on YOUR website!
Let x = number of hours driving until they meet.
Distance of Sandy = R*T = 60x
Distance of Kelvin = R*T= 50x

Total Distance = 385 miles
60x + 50x = 385
110x = 385
x=385/110=3 55/110
x=3.5 hours
Since they left at 3:00 pm, add 3.5 hours, and they will meet at 6:30 pm.

For additional explanation on Word Problems, please see my own website. Look for the easy-to-remember and easy-to-spell link www.mathinlivingcolor.com. At the bottom of this page is a link that takes you to my Homepage. Near the top of the Homepage, look for the link: "Basic, Intermediate, and College Algebra: One Step at a Time." Choose "Basic Algebra" and look in Chapter 1, for Section 1.10 Word Problems.

You will probably like my explanations, especially the PRICE of them!! They are ALL FREE!! My own students before my retirement thought my books were easier to understand than the traditional books, and many of the solutions are given IN COLOR in the attached "Math in Living Color" pages.

Most any algebra topic you need is probably there somewhere. If you need help finding the right page on the website, please send me an Email at rapaljer@seminolestate.edu. If you like my website, please recommend it to family and friends.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Problems-with-consecutive-odd-even-integers/632366: find the four consecutive integers such that the sum of the second and the third is 68.
1 solutions

Answer 398233 by rapaljer(4667) About Me  on 2012-07-27 09:17:33 (Show Source):
You can put this solution on YOUR website!
Let x = first
x+1 = second
x+2 = Third
x+3 = fourth

Second + Third = 68
x+1 + x+2 = 68
2x + 3 = 68
2x = 65
x= 32.5 Not an integer!

There is NO SOLUTION!!

For additional explanation on Word Problems, please see my own website. Look for the easy-to-remember and easy-to-spell link www.mathinlivingcolor.com. At the bottom of this page is a link that takes you to my Homepage. Near the top of the Homepage, look for the link: "Basic, Intermediate, and College Algebra: One Step at a Time." Choose "Basic Algebra" and look in Chapter 1, for Section 1.10 Word Problems.

You will probably like my explanations, especially the PRICE of them!! They are ALL FREE!! My own students before my retirement thought my books were easier to understand than the traditional books, and many of the solutions are given IN COLOR in the attached "Math in Living Color" pages.

Most any algebra topic you need is probably there somewhere. If you need help finding the right page on the website, please send me an Email at rapaljer@seminolestate.edu. If you like my website, please recommend it to family and friends.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Graphs/632276: solve the inequality m+1/4 ≤ 1/2 what am i supposed to do?
1 solutions

Answer 398175 by rapaljer(4667) About Me  on 2012-07-26 22:56:44 (Show Source):
You can put this solution on YOUR website!
Subtract 1/4 from each side:

m%2B1%2F4+-1%2F4+%3C=1%2F2-1%2F4
m%3C=1%2F4

Draw a numberline, locate the number at m=1/4, shade everything that is to the LEFT of 1/4 and INCLUDE the endpoint.

For additional explanation on Inequalities, please see my own website. Look for the easy-to-remember and easy-to-spell link www.mathinlivingcolor.com. At the bottom of this page is a link that takes you to my Homepage. Near the top of the Homepage, look for the link: "Basic, Intermediate, and College Algebra: One Step at a Time." Choose "Basic Algebra" and look in Chapter 1, for Section 1.11 Inequalities.

You will probably like my explanations, especially the PRICE of them!! They are ALL FREE!! My own students before my retirement thought my books were easier to understand than the traditional books, and many of the solutions are given IN COLOR in the attached "Math in Living Color" pages.

Most any algebra topic you need is probably there somewhere. If you need help finding the right page on the website, please send me an Email at rapaljer@seminolestate.edu. If you like my website, please recommend it to family and friends.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Travel_Word_Problems/632280: A vehicle is traveling 35 mph. It takes that vehicle 12 minutes to reach its destination. How far away is that distance (in miles).
I am unsure how to do this type of math problem. Can you please explain it to me.
1 solutions

Answer 398174 by rapaljer(4667) About Me  on 2012-07-26 22:46:08 (Show Source):
You can put this solution on YOUR website!
The key is to make sure the units in the problem are the same throughout the problem. Since you have 35 mph, you need to change the 12 minutes to 12/60 = 1/5 hour.

Now, use the famous formula D=RT, where R=35 mi/hr and T=1/5 hour.

D=RT
D=35*1/5 = 7 miles

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Linear_Equations_And_Systems_Word_Problems/632268: Hello! Just want to ask about how to solve different problems (like geometry,two-digit,age,mixture,motion and investment related problems) involving systems of linear equations
1 solutions

Answer 398173 by rapaljer(4667) About Me  on 2012-07-26 22:41:03 (Show Source):
You can put this solution on YOUR website!
For additional explanation on this topic, please see my own website. Look for the easy-to-remember and easy-to-spell link www.mathinlivingcolor.com. At the bottom of this page is a link that takes you to my Homepage. Near the top of the Homepage, look for the link "Basic, Intermediate, and College Algebra: One Step at a Time." Choose Basic Algebra, look in Chapter 4 for Section 4.08 Applications of Systems of Equations. Several examples are solved IN COLOR, which you should find helpful.

If you like the website, please recommend it to your friends and family.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Permutations/632277: at a local resaturant a new dinner menu is available that offers 4 courses an appetizer a salad a main dish and a dessert all for one price there are 7 appetizers 2 salads 4 main dishes and 4 desserts how many dinner outcomes are possible
1 solutions

Answer 398172 by rapaljer(4667) About Me  on 2012-07-26 22:34:44 (Show Source):
You can put this solution on YOUR website!
You multiply the numbers of outcomes for each category:

Main Dishes * Appetizers * Salads * Desserts
4*7*2*4 = 224

For additional explanation on this topic, please see my own website. Look for the easy-to-remember and easy-to-spell link www.mathinlivingcolor.com. At the bottom of this page is a link that takes you to my Homepage. Midway down my Homepage look for the link "Topics from Probability." Everything is FREE!!

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida



Radicals/631626: sqrt2,3sqrt3,6sqrt6,12sqrt12
which is smallest explain it
1 solutions

Answer 397718 by rapaljer(4667) About Me  on 2012-07-24 23:23:28 (Show Source):
You can put this solution on YOUR website!
sqrt 2 has the smallest coefficient AND also the smallest radicand. Therefore it must be the smallest quantity.

For additional help with a variety of algebra topics, please see my own FREE website which can be found at the easy-to-remember and easy-to-spell link: www.mathinlivingcolor.com. Click on the link near the bottom of the page, which will take you to my Homepage. Near the top of the papge, look for the link "Basic, Intermediate, and College Algebra: One Step at a Time."

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Angles/631625: The sum of the measures of a complement and supplement of an angle is 200. What is the measure of the angle?
1 solutions

Answer 397714 by rapaljer(4667) About Me  on 2012-07-24 23:11:26 (Show Source):
You can put this solution on YOUR website!
Let x=the angle
90-x=the compliment
180-x=the supplement

90-x + 180-x = 200
270 - 2x =200
-2x = -70
x=35 The angle
90-x =55 The Complement
180-x = 145 The Supplement

Check: 55 + 145 = 200 It checks!!

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Finite-and-infinite-sets/631589: Use the addition principle for counting to solve the problem:
If n(A)=20, n(A U B)=58, and n(A "intersection" B)=16, Find n(B)
1 solutions

Answer 397690 by rapaljer(4667) About Me  on 2012-07-24 20:23:55 (Show Source):
You can put this solution on YOUR website!
In order to get the UNION of two sets, you can ADD the number of members of the two sets together, and SUBTRACT the OVERLAP. The OVERLAP is actually the INTERSECTION. This gives the following formula:

n(A) + n(B)-n(A intersection B)=n(AUB)
20 + n(B) -16 = 58
4 + n(B) = 58
n(B) = 58-4 = 54

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Linear_Equations_And_Systems_Word_Problems/631574: S=a+b/2h for h
1 solutions

Answer 397688 by rapaljer(4667) About Me  on 2012-07-24 20:16:12 (Show Source):
You can put this solution on YOUR website!
S=%28a%2Bb%29%2F%282h%29

Multiply both sides of the equation by the denominator 2h:
2h%2AS=%28a%2Bb%29

To solve for h, divide both sides by 2S:
h=%28a%2Bb%29%2F%282S%29+

For additional help with Literal Equations, please see my own FREE website which can be found at the easy-to-remember and easy-to-spell link: www.mathinlivingcolor.com. Click on the link near the bottom of the page, which will take you to my Homepage. Near the top of the Homepage, look for the link "Basic, Intermediate, and College Algebra: One Step at a Time." Choose Intermediate Algebra, and look in Chapter 3 for the section on Literal Equations.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


sets-and-operations/631585: Write each statement in symbolic form using the indicated letters to represent the corresponding components.
Snoopy is not an aviator (~a), or the Sopwith Camel is an airplane( p).
1 solutions

Answer 397686 by rapaljer(4667) About Me  on 2012-07-24 20:04:46 (Show Source):
You can put this solution on YOUR website!
~aVp

For additional help with Logic, please see my own FREE website which can be found at the easy-to-remember and easy-to-spell link: www.mathinlivingcolor.com. Click on the link near the bottom of the page, which will take you to my Homepage. About halfway down the Homepage, look for the link "Topics from Logic."

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


sets-and-operations/631584: Section 3.3: #6. Find the truth value of the following statement:
If 2 + 2 = 22, then 8 = 4 + 4
1 solutions

Answer 397685 by rapaljer(4667) About Me  on 2012-07-24 19:58:51 (Show Source):
You can put this solution on YOUR website!
If the hypothesis of an if-then statement is FALSE, then the truth value of the statement is ALWAYS TRUE!!

For additional help with LOGIC, please see my own FREE website which can be found at the easy-to-remember and easy-to-spell link: www.mathinlivingcolor.com.

There is an entire section on "Topics from Logic" that may be helpful.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Functions/630458: Please help me with this problem, using the piecewise function:
f(x)= $5o if o< x < 60
4/3x - 30 if x > 60
this function describes the rate of a computer repairman.
The question is what is the cost if the repairman works for 45 minutes?
Thanks.
1 solutions

Answer 396922 by rapaljer(4667) About Me  on 2012-07-20 22:42:24 (Show Source):
You can put this solution on YOUR website!
Since 45 minutes is BETWEEN 0 and 60 minutes, you use the first half of the formula, which is a flatrate $50. However, if the computer repairman runs OVER 60 minutes, then you use the rate of 4/3 x - 30. In other words, if it takes more than 60 minutes, they charge EXTRA, depending upon how long it takes. For example, if it takes 66 minutes, then you calculate 4/3*66-30, which is $58.

For additional help with most algebra topics, please see my own FREE website which can be found at the easy-to-remember and easy-to-spell link: www.mathinlivingcolor.com.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Miscellaneous_Word_Problems/630292: AB + BA= 1A4
in the correctly worked addition problem above, A and B represent two different digits. what digit does A represent?
*please include explanations
1 solutions

Answer 396814 by rapaljer(4667) About Me  on 2012-07-20 12:26:23 (Show Source):
You can put this solution on YOUR website!
The value of AB is 10A + B, while the value of BA is 10B + A.

In the equation, AB + BA = 1A4, substitute the values of AB and BA above:
(10A + B) + (10B + A) = 100 + 10A + 4

Subtract 10A from each side:
B+ 10B + A = 104
11B + A = 104

Subtract A from each side:
11B = 104 - A

Since B must be an integer, this means that you must subtract an integer value of A from 104 and obtain a multiple of 11.

If A = 1, you have 11B=103. 103 is not a multiple of 11.
If A = 2, you have 11B=102.
If A = 3, you have 11B=101.
If A = 4, you have 11B=100.
If A = 5, you have 11B=99, so B = 9. It works!!

Check: AB= 59, BA= 95,

AB + BA = 1A4
59 + 95 = 154, so it checks!!

Congratulations on a NICE PROBLEM!! I liked this one VERY MUCH!!

For additional help with this topic and other algebra topics, please see my own FREE website at www.mathinlivingcolor.com.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Circles/630246: Calculate the radius of a circle whose area is equal to the sum of the areas of three?
circles of radii 2 cm, 3 cm and 4 cm.
1 solutions

Answer 396809 by rapaljer(4667) About Me  on 2012-07-20 12:10:41 (Show Source):
You can put this solution on YOUR website!
A=pi%2Ar%5E2

Area of three circles = pi%2A2%5E2+%2B+pi%2A3%5E2+%2B+pi%2A4%5E2
A=pi%2A4+%2B+pi%2A9+%2B+pi%2A16
A=pi%2A29

Area of unknown circle = pi%2Ar%5E2=pi%2A29

Divide both sides by pi:

r%5E2=29

r=sqrt%2829%29+

For additional help with this topic and other algebra topics, please see my own FREE website at www.mathinlivingcolor.com.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Linear-equations/630254: Is (1,-3) a solution of y=-2x-1?
1 solutions

Answer 396806 by rapaljer(4667) About Me  on 2012-07-20 11:29:04 (Show Source):
You can put this solution on YOUR website!
The point (1,-3) means to substitute x=1, and see if y=-3.

y=-2x-1
y=-2(1)-1
y=-2-1=-3. YES!!

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Probability-and-statistics/630275: How many different teams of 2 people each can Joshua select from a group of 5 people?
please include explanations!
1 solutions

Answer 396805 by rapaljer(4667) About Me  on 2012-07-20 11:24:19 (Show Source):
You can put this solution on YOUR website!
Since you are choosing members of a team (the key word here is "CHOOSE"!), it is a COMBINATION problem, a combination of 5 people, taken 2 at a time.

C(5,2) = %285%2A4%29%2F%282%2A1%29 = 10.

Most calculators of today will calculate combinations and permuations for you.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Triangles/630277: the length of the base of a triangle, x-8, is less than the height of triangle, 12.
1 solutions

Answer 396803 by rapaljer(4667) About Me  on 2012-07-20 11:20:04 (Show Source):
You can put this solution on YOUR website!
What was the question? Is there more information or a diagram in this problem?

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


absolute-value/630278: |x + 2| + 16 = 14
1 solutions

Answer 396802 by rapaljer(4667) About Me  on 2012-07-20 11:18:19 (Show Source):
You can put this solution on YOUR website!
In order to isolate the absolute value, subtract 16 from each side.
This gives
abs%28x%2B2%29=-2

Since absolute value cannot equal a negative number, there is NO SOLUTION.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida


Functions/614727: Under what circumstances would the domain be something other than all real numbers? Provide an example.

1 solutions

Answer 386670 by rapaljer(4667) About Me  on 2012-05-24 22:54:19 (Show Source):
You can put this solution on YOUR website!
For functions in which there are NO DENOMINATORS and NO SQUARE ROOTS, the DOMAIN is ALL REAL NUMBERS. An example would be y=x^2.

However, if you have a variable in a DENOMINATOR, like y=3%2F%28x-5%29, then the domain is all values of x except x=5.

If you have a square root, like y=sqrt%28x-5%29, then there is a restriction that the radicand, which is x-5, must be greater than or equal to zero. That is, x-5%3E=0. This means x%3E=5. I have a similar explanation with more details on my website.

You might want to see my own NON-TRADITIONAL explanation of FUNCTIONS, DOMAIN, and RANGE on my own website. To find my website, use the easy-to-spell and easy-to-remember link www.mathinlivingcolor.com. This link takes you to a single page with a single link near the bottom of the page. Click on this link, and it takes you to my Homepage.

Once you are on my Homepage, look for "Basic, Intermediate, and College Algebra: One Step at a Time." Choose "Intermediate or College Algebra", and look in "Chapter 5" for Intermediate Algebra, and Chapter 2 for College Algebra. Then, the hardest of the problems in these sections are solved IN COLOR on the Math in Living Color page for the respective sections.

On the topic of Functions, Domain and Range, I also have VIDEOS of me teaching this topic a few years before I retired. To find the videos, look on my Homepage for "Rapalje Videos in Living Color." Look in Intermediate or College Algebra respectively for the video on Functions, Domain, and Range. The videos, like everything else on my website, are all FREE!!! Check it out!! Math is usually not as hard as it looks if you get a decent explanation of it!!

I hope this is helpful. For ANYONE interested in using my FREE website for ANY TOPIC in math, just send me an Email at rapaljer@seminolestate.edu.

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida
Altamonte Springs Campus