New!
Get regular updates about newly solved problems
via algebra.com's RSS system.
Recent problems solved by 'mangopeeler07'
mangopeeler07 answered: 461 problems
Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149 , 150..179 , 180..209 , 210..239 , 240..269 , 270..299 , 300..329 , 330..359 , 360..389 , 390..419 , 420..449 , 450..479, >>Next
test/477921: What is the area of a square that has sides 14 centimeters in length? 1 solutions
Answer 327493 by mangopeeler07(462) on 2011-08-04 15:19:57 (Show Source):
You can put this solution on YOUR website!If it's a square, all the sides are the same length. So the area of a square is the length times the height (or the length squared).
Area= 196 centimeters squared
|
Age_Word_Problems/477916: My age is now four times yours, but five years ago it was five times yours. how old was the man? 1 solutions
Answer 327490 by mangopeeler07(462) on 2011-08-04 15:13:20 (Show Source):
You can put this solution on YOUR website!M=my age
Y=your age
My age is now four times yours:

But five years ago it was five times yours:

Plug in 4Y for M:

Simplify both sides

So "your age" is 20. "My age" is 80.
If you check it, that works. Five years ago "you" would have been 15 and "my age" would have been 75. 15*5=75
|
Linear_Equations_And_Systems_Word_Problems/477895: Walt made an extra $9000 last year from a part-time job. He invested part of the money at a 9% annual rate of interest, and the rest at 8% annual rate of interest. At the end of the year, he made a total of $770 in interest. How much was invested at 8%?
1 solutions
Answer 327462 by mangopeeler07(462) on 2011-08-04 14:33:54 (Show Source):
You can put this solution on YOUR website!9000=total money
Money at 9%=x
Money at 8%=9000-x (because it's the rest)
increase interest=770. so 9000+770= 9770.
So set up the equation:
 Because x+ 9% of x and (9000-x) + 8% of that equals 9770.
Simplify
Simplify again
Subtract 9720 from both sides.
Divide each side by .01
Therefore:
$5000 was invested at 9%, and $4000 was invested at 8%.
|
Word_Problems_With_Coins/477880: HOw many ways can you make 25 cents ONLY using pennies, nickels & dimes? And can you list them
1 solutions
Answer 327461 by mangopeeler07(462) on 2011-08-04 14:25:30 (Show Source):
You can put this solution on YOUR website!1 dime 3 nickels
1 dime 15 pennies
1 dime 1 nickel 10 pennies
1 dime 2 nickels 5 pennies
2 dimes 5 pennies
2 dimes 1 nickel
1 nickel 20 pennies
2 nickels 15 pennies
3 nickels 10 pennies
4 nickels 5 pennies
5 nickels
25 pennies
|
Linear_Equations_And_Systems_Word_Problems/477893: Half of the cows are grazing grass .Three-fourth of the remaining are sleeping and 9 cows are drinking water from the pond.Find the total number of cows. 1 solutions
Answer 327460 by mangopeeler07(462) on 2011-08-04 14:18:09 (Show Source):
You can put this solution on YOUR website!Set C as the total number of cows. Set G as the grazing cows, S as the sleeping cows, and D as the drinking cows. Set up the equation like so;
Total numbers of cows=all grazing, sleeping, and drinking cows.
Half the total cows are grazing:
Three fourths of the REMAINING cows are sleeping
9 cows are drinking from the pond
Plug all these answers into the original equation  and get
Now simplify:
Combine all the C's on both sides:
Now multiply both sides by 8:
Answer: 72 cows
To check, plug in 72 for C.
There are 72 cows, if half of them are grazing, then 36 are grazing. If three-fourths of the rest (36 more) are sleeping, then 27 are sleeping, which leaves 9 drinking.
|
Mixture_Word_Problems/477890: A lunch menu consists of 3 different sandwiches, 2 different soups, and 4 different drinks. How many choices are there for ordering a sandwich, a bowl of soup, and a drink? 1 solutions
Answer 327458 by mangopeeler07(462) on 2011-08-04 14:09:35 (Show Source):
You can put this solution on YOUR website!Think of it this way. Take it one at a time. For every one sandwich, there are two different soups you can have (disregard the drinks for now). That's two combinations, for three sandwiches, so three times two, which gives you six.
Now, for every one sandwich and one drink (six), there are four different drinks you can choose from. Six times four is 24.
In other words, multiply all the numbers together.
|
Inverses/477888: What is the inverse of f(x)=(x-7)^3
I know you change out f(x) to y: y=(x-7)^3
Then swap x and y: x=(y-7)^3...But now I am stuck as to what numbers will come back over with y..Can you help? 1 solutions
Answer 327455 by mangopeeler07(462) on 2011-08-04 14:02:06 (Show Source):
You can put this solution on YOUR website!You got to  okay. Then you would have to solve for y.
Take the cube root of both sides:
And now add 7 to both sides:
Flip it for sanity's sake:
Now change y to f(x) and voila!!
Answer:
|
Inequalities/271365: Write an inequality to represent this situation. Louis makes $30 for each yard he mows and $20 for each lawn he weeds. He wants to make atleast $150 each week. 1 solutions
Answer 198690 by mangopeeler07(462) on 2010-02-18 16:35:08 (Show Source):
You can put this solution on YOUR website!Louis makes 30 dollars per yard mowed, so his profit from that is 30 times the number of yards or  . Louis makes 20 dollars per lawn weeded, so his profit from that is 20 times the number of lawns or  . Added all together  he wants at least 150 dollars.
Solution:
|
Polynomials-and-rational-expressions/181917: This question is from textbook algebra 1
martha has $6000 to invest. she puts x dollars of this money into a savings account that earns 3% per year, and with the rest, she buys a certificate of deposit that earns 6% per year. suppose at the end of one year, martha has a total of $6315. how much money did martha invest in each account? 1 solutions
Answer 136583 by mangopeeler07(462) on 2009-02-14 20:12:41 (Show Source):
You can put this solution on YOUR website!x---money invested at 3%
y---money invested at 6%
1x+1y=6000----------b/c she has 6000 to invest
1.03x+1.06y=6315-------------b/c of the percent of investment and the final amount of money
solve eq. 1 for x
x=6000-y
plug that in to the second eq.
1.03(6000-y)+1.06y=6315
Distribute
6180-1.03y+1.06y=6315
Combine like terms
.03y=135
Solve for y
y=4500
x=6000-y
x=6000-4500
x=1500
Check answers:
x+y=6000
1500+4500=6000-------true
1.03(1500)+1.06(4500)=6315-----true
-------------------------------------------
Answers:
money invested at 3%----$1500
money invested at 6%----$4500
|
Graphs/175005: What is the equation with the points (4,0) and (0,-4)? 1 solutions
Answer 130092 by mangopeeler07(462) on 2009-01-04 19:11:12 (Show Source):
You can put this solution on YOUR website!y=mx+b
First find the slope (m) using the difference of the y's over the difference of the x's.
so the slope is 1
y=x+b
Plug in one of the points, it doesn't matter which one.
0=4+b
Solve for b
b=-4
Answer:
y=x-4
|
Polynomials-and-rational-expressions/174979: V=0.104h-0.018a-2.69
(a)age=14
(h)hieght=67"
Solve the formula for age(a). Estimate how old you will be when your air volume is 90% of its current volume.
(use current hieght) 1 solutions
Answer 130091 by mangopeeler07(462) on 2009-01-04 19:07:31 (Show Source):
You can put this solution on YOUR website!(a)age=14
(h)hieght=67"
Solve the formula for age(a). Estimate how old you will be when your air volume is 90% of its current volume.
(use current height)
solve the formula for a:
V=0.104h-0.018a-2.69
V+2.69=0.104h-0.018a
V+2.69-0.104h=-0.018a

----------------------------------------------
Solve for V so you can plug 90% of it in later...
V at a=14 and h=67:
V=0.104h-0.018a-2.69
V=0.104(67)-0.018(14)-2.69
V=4.026
----------------------------------------------
a for h=67 and .9V when V=4.026--------->90% of V
V=0.104h-0.018a-2.69
.9V=(0.104h-0.018a-2.69)
.9(4.026)=(0.104(67)-0.018a-2.69)
3.6234=6.968-.018a-2.69)
3.6234=4.278-.018a
-.6546=-.018a
36.4=a
|
Linear-equations/169837: Two-thirds of a number is less than eight. Find the largest integer that will satisfy the inequality.
A. 12
B. 11
C. 10
D. 13 1 solutions
Answer 125227 by mangopeeler07(462) on 2008-11-26 17:26:29 (Show Source):
You can put this solution on YOUR website!Two-thirds of a number is less than eight. Find the largest integer that will satisfy the inequality.
A. 12
B. 11
C. 10
D. 13
First find: two-thirds of x is eight. Once you do that, the solution to: "Two-thirds of a number is less than eight" would be any number less than x.
"Two-thirds of a number is less than eight"---the number is less than x, which is 12, so it would anything 11 and under.
So the largest integer to satisfy that would be 11.
|
Geometry_Word_Problems/169153: This question is from textbook Elementary and Intermediate Algebra
Can you tell me what the perimeter of a rectangular backyard is that is
6x + 6 yards. If the width is x yards, can you please find a bionomial that
represents the length. Thanks! 1 solutions
Answer 124762 by mangopeeler07(462) on 2008-11-23 15:27:41 (Show Source):
You can put this solution on YOUR website!Can you tell me what the perimeter of a rectangular backyard is that is
6x + 6 yards. If the width is x yards, can you please find a bionomial that
represents the length. Thanks!
The perimeter is 2 times the width plus 2 times the length. If the width is x and the perimeter is 6x+6, than the expression that equals the length would be:
The expression above is derived from the following:
Now simplify the expression  :
|
Functions/169171: Marlena is making her own bracelets. Each bracelets will have 10 beads. WRite a function rule to describe the number of beads she will use. Find a reasonable domain and range for the fuction if Marlena makes up to 7 bracelets. 1 solutions
Answer 124758 by mangopeeler07(462) on 2008-11-23 15:15:46 (Show Source):
You can put this solution on YOUR website!"Marlena is making her own bracelets. Each bracelet will have 10 beads. Write a function rule to describe the number of beads she will use. Find a reasonable domain and range for the fuction if Marlena makes up to 7 bracelets."
We'll have "x" be the number of bracelets and "y" be the number of beads.
"Marlena makes up to 7 bracelets": because of this statement, we know that x, the number of bracelets, may not go over 7.
Logically, Marlena cannot make a negative number of bracelets, so we also know that x has to be more than (or equal to) 0.
So our logical domain would be:

----------------------------------------------------
We know that each bracelet has ten beads, so the amount of beads used would be ten times the amount of bracelets, or  ---in f(x) form, this is the function---->  .
To get the logical range, all we have to do is use the logical domain, which we already have, and use the same inequality signs.
Plug in 7 and 0, our logical domain, for x to get the logical range, y.
So the logical range would be

--------------------------------------------
Domain: 
Range:
|
Expressions-with-variables/164690: The cashier in a movie box office sold 200 more adult admission tickets at $11.00 each than children admission tickets at $8.00 each. What is the minimum number of each type of ticket that the cashier can sell for the total receipts to be at least $5000. 1 solutions
Answer 121361 by mangopeeler07(462) on 2008-10-29 16:40:46 (Show Source):
You can put this solution on YOUR website!200 more adult admission tickets...than children admission tickets:
a=c+200
adults=$11 each
children=$8 each
total receipts=at least $5000
System:
a=c+200
Use substitution
Distribute
Combine like terms
Subtract 2200 from both sides
Divide both sides by 19
 --------this is rounded up from 147.3, since you can't sell .3 of a ticket.
a=c+200
a=148+200
a=348
 ----since c might be more than 148.
Answer:
148 childrens tickets
348 adults tickets
|
Equations/158070: This question is from textbook prentice hall mathematics algebra 1
a passenger train's speed is 60 mi/h, and a freight train's speed is 40 mi/h. the passenger train travels the same distance in 1.5 h less time than the freight train. How long does each train take to make the trip?
1 solutions
Answer 116468 by mangopeeler07(462) on 2008-09-20 17:57:09 (Show Source):
You can put this solution on YOUR website!h=amount of hours
mph(h)=distance
the passenger train travels the same distance (set equal to each other) in 1.5 h less time than the freight train.
Simplify each side by multiplying
Eliminate the denominators, since they are the same thing
Subtract 60h from both sides
Divide both sides by -20
Passenger train: (h-1.5)
Freight train: (h)
Plug in 4.5 for h
4.5-1.5=3.0
---------------------------------------------------------
Answer:
Passenger train= 3 hours
Freight train= 4.5 hours
|
Expressions-with-variables/158072: Admission to a park is x dollars per person for the first 3 people in a group and y dollars per person for each additional person.
write a formula for the total cost c when the number of people in a group p
is more than 3 1 solutions
Answer 116467 by mangopeeler07(462) on 2008-09-20 17:42:25 (Show Source):
You can put this solution on YOUR website!Admission to a park is x dollars per person for the first 3 people in a group and y dollars per person for each additional person.
write a formula for the total cost c when the number of people in a group p
is more than 3
------------------------------------------------------------------------------
3x would be the cost for the first three people.
ny would be the cost of the rest, for which n would be the number of people in the group minus three, because three people are already paid for.
There are p people in the group, so ny becomes (p-3)y.
Add those prices together to get the total price for one group.
|
Functions/156686: The problem is: Evaluate and find the domain. f(x)=1/x^2-9 for x=4,a-5
I am able to evaluate and came up with f(4)=1/7 and f(4)=1/a^2-10a+16. What I don't understand is how to find the domain. I know my book says the answer is: x is not equal to 3, and x is not equal to -3. I just don't know how the domain came to be this, I don't understand how to find the domain. Please help.
1 solutions
Answer 115505 by mangopeeler07(462) on 2008-09-13 13:41:20 (Show Source):
You can put this solution on YOUR website!f(x)=1/x^2-9
To find the domain, you would have to find [what x can be without making the denominator zero]. So set the denominator, x^2-9, equal to zero:
x^2-9=0
Now factor out the left side.
(x-3)(x+3)=0
Now take each expression separately and set them equal to zero and solve.
x-3=0
x=3
x+3=0
x=-3
So to make the denominator zero, x would have to be 3 or -3. So to get the domain, "what x can be without making the denominator zero", you would say anything but these two values. In other words:
x is not 3 or -3.
Do you follow?
I hope this helped!
-Alani
|
Mixture_Word_Problems/156684: Thanks for any insight you may be able to give me...
This question is from a quiz my instructor gave to us. He says the questions come from a textbook.
How many liters of a 70% acid solution are needed to be mixed with 18 liters of a 10% acid solution to get a mixture which is 25% alcohol?
If the solution contains acid/alcohol you would need 75% acid to leave you with 25% alcohol. How is it even possible to get 75% when both solutions you are using are diluted below 75%. As far as I have tried I see no possible solution to this problem, if he meant 25% acid then it would be easy to answer.
Let me know what you think, thanks for your time,
Bill W 1 solutions
Answer 115502 by mangopeeler07(462) on 2008-09-13 13:35:38 (Show Source):
You can put this solution on YOUR website!How many liters of a 70% acid solution are needed to be mixed with 18 liters of a 10% acid solution to get a mixture which is 25% alcohol?
Alcohol? Yes, he probably meant to say "acid". Let's work it out for acid.
How many liters of a 70% acid solution are needed to be mixed with 18 liters of a 10% acid solution to get a mixture which is 25% ACID?
(amount of liters)
coefficient=percent
70(x)+10(18)=25(x+18)
Distribute everything.
70x+180=25x+450
Subtract 25x from both sides
45x+180=450
Subtract 180 from both sides
45x=270
Divide both sides by 45
x=6
Answer: 6 liters
---------------------------------------------------
Now let's assume he actually meant alcohol. 25% alcohol means 75% acid. So:
(amount of liters)
coefficient=percent
70(x)+10(18)=75(x+18)
Do you follow?
25 is changed to 75 because it is 75% acid now.
Distribute, like before
70x+180=75x+1350
Subtract 75x from both sides
-5x+180=1350
Subtract 180 from both sides
-5x=1170
Divide by -5
x=-234
Negative means you would have to subtract, and logically speaking, you wouldn't take away acid to increase the percentage of acid. Therefore, the logical answer is:
6 liters
-------------------------------------------------------
I hope this helped!
-Alani
|
Trigonometry-basics/156672: from the top of a fire tower, the angle from your hoizontal line of sight down to the fire on the ground is what angle? 1 solutions
Answer 115499 by mangopeeler07(462) on 2008-09-13 13:24:05 (Show Source):
You can put this solution on YOUR website!You would have to know the height of the building and the proximity of the fire to the building. Then to find the angle, you would have to do the inverse tangent function. You do that by taking your calculator and pushing the "2nd" button, then the "TAN" button. Then enter in the value or fraction for [(how far the fire is from the building)/(the height of the building)], in other words, the opposite over the adjacent of this angle. Close the parentheses and press "ENTER". The value you get is the measure of the angle.
I hope this helped!
-Alani
|
|