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Rational-functions/158257: This question is from textbook college algebra
In fact, I have to solve problem 26, but some information are found in problem 25.here they go.
25) Suppose ABC car rental charges a fixed amount per day plus an amount per mile for renting a car.Heidi rented a car one day and paid $87 for 200 miles. On another day, she rented a car from the same agency and paid $117.50 for 350 miles.Determine the linear function that the agency could use to determine its daily rental charges.
now, the real problem 26) Suppose that Heidi (of problem 25) also has access to speedy car rental, which charges a daily fee of $15.00 plus $ 0.31 per mile.Should Heidi use ABC Car rental from problem 25 or speedy car rental?
well, I started by find 25)f(x)=0.25x+30 and I tried to use f(x)=0.31x+15,with no results.
1 solutions
Answer 116675 by scott8148(6628)   on 2008-09-22 00:13:55 (Show Source):
You can put this solution on YOUR website!it depends on the miles she drives
speedy has a lower daily fee, but charges more per mile
if you set the two functions equal to each other, you can solve for the miles at which point it is cheaper to rent from ABC
you should check your numbers for the ABC rental function
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Exponents/158267: If i simplify x^7y^9z^3 over x^4y^7z^8 it would be x^3y^2z^-5
and to make it positive i would have to make z^-5 the denominator to make it z^5 but what happens to the x^3y^2 ? does it become the numerator?
1 solutions
Answer 116674 by scott8148(6628) on 2008-09-22 00:02:22 (Show Source):
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Word_Problems_With_Coins/158293: Susan has saved $85.75 in quarters and loonies. She has one quarter more than three-fourths the number of loonies, how many coins of each type does she have.
I have tried this a zillion times using 2 separate equations and the elimination method a variety of ways, but cannot seem to get an answer that fits back. If someone can show me the proper equation to be using please then I can solve from there.
Thanks.
1 solutions
Answer 116671 by scott8148(6628) on 2008-09-21 23:52:28 (Show Source):
You can put this solution on YOUR website!"Susan has saved $85.75 in quarters and loonies" __ .25Q+1L=85.75 __ 25Q+100L=8575
"She has one quarter more than three-fourths the number of loonies" __ Q=.75L+1 __ 100Q=75L+100
***SOLUTION HERE***
multiplying 1st eqn by 4 __ 100Q+400L=34300 __ substituting __ (75L+100)+400L=34300
475L=34200 __ L=72
substituting __ .25Q+(72)=85.75 __ .25Q=13.75 __ Q=55
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Triangles/158298: I have a triangle and the sides are 150 cm 175 cm and 200 cm. I have 25 similar trianles that I need to use to tile the entire area of this triangle. I am supposed to tell the lenghts of the sides of the small triangles used in the tiling and explain how I figured it out. I think that the sides are 6cm 7cm and 8cm each, but I'm not sure how I got that. Am I going in the right direction and if so, how do I explain it.
1 solutions
Answer 116668 by scott8148(6628) on 2008-09-21 23:34:23 (Show Source):
You can put this solution on YOUR website!the ratio of the areas of similar figures is the square of the ratio of their side lengths
look at a square of side length s, the area is s^2
__ if you double the side length, the area is 2s*2s or 4s^2
__ doubling the side length, quadruples the area (square relation)
if the area of a tiling triangle is 1/25, then the side length must be 1/5
__ 1/5 squared is 1/25
so the side lengths are 30cm, 35cm, and 40cm
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Miscellaneous_Word_Problems/157960: Rita State is selling her home. Since she hired a realtor, she must pay 6% of the purchase price to the realtor. If Rita wants to have at least $180,000 left after paying the realtor, what is the minimal amount (to the correct dollar) to set the purchase price? (ignore tax, etc)
PLEASE HELP WITH EXACT STEPS!
1 solutions
Answer 116429 by scott8148(6628) on 2008-09-20 07:00:10 (Show Source):
You can put this solution on YOUR website!the realtor gets 6%, so Rita keeps 94% __ let x=purchase price
the minimum purchase price will leave Rita with $180000 __ (94%)x=180000
dividing by .94 __ x=191490
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test/157871: hey i would highly appreciate it if you could help me with this complex probability question:
A choir consists of 20 girls and 15 boys. A committee of 4 people is selected from the choir.
a) What is the probability that there are only boys on the committee?
b) What is the probability that there is at least 1 boy on the committee?
c) What is the probability that there are exactly 3 girls on the committee?
1 solutions
Answer 116345 by scott8148(6628) on 2008-09-19 11:46:55 (Show Source):
You can put this solution on YOUR website!how many groups of 4 out of 35 people __ 35C4 __ 52360
a) how many groups of 4 out of 15 __ 15C4 __ 1365
__ probability of all boys __ 1365/52360=.026 (approx)
b) how many groups of 4 out of 20 people __ 20C4 __ 4845
__ probability of all girls __ 4845/52360 __ .093 (approx)
__ probability of at least 1 boy __ 1 minus probability of no boys (all girls) __ 1-.093=.907
c) how many groups of 3 out of 20 people __ 20C3 __ 1140
__ each group of 3 girls with any of 15 boys __ 1140*15=17100
__ probability of exactly 3 girls __ 17100/52360=.327 (approx)
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Radicals/157166: hello i am having trouble trying to solve radicals with letters in them.(i know there is mathmatical word for letters i just forgot) here is one of the questions.
the square root of 360x^5y^4
thank you
1 solutions
Answer 115827 by scott8148(6628) on 2008-09-15 17:51:25 (Show Source):
You can put this solution on YOUR website!remember sqrt(ab)=sqrt(a)*sqrt(b) and set up whole roots by factoring
sqrt(360x^5y^4)=sqrt(6^2*10*(x^2)^2*x*(y^2)^2)=6x^2y^2(sqrt(10x))
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Finance/156983: OFF TOPIC QUESTION! SORRY!
I'm really sorry to be asking this here as I know that it is a math homework help website. However, I have an english homework question. I have four sentences from an essay that have an error in them somewhere and I can't figure out where. I dont expect anyone here to help me, but i would really apperciate it if any of you might know of a helpful site like this for english? I really appericiate you all taking your time to help students and I thought you might know of a place that could help. Thank you so much!!
I need to revise these sentences and I can’t figure out what I did wrong. Thanks!
At the same time, a five foot five, one hundred
and fifty pound, average women passes by.
Of course the first women with her lanky body
and perfect bone structure is going to stand out.
While the first women should still be the one to
stand out as unusual, it’s the opposite.
The average women would be seen as odd,
undesirable, and unwanted.
1 solutions
Answer 115806 by scott8148(6628) on 2008-09-15 11:15:55 (Show Source):
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Mixture_Word_Problems/156804: A chemist has two acid solutions.One contains 15 percent acid and the other contains 6 percent acid. How many cubic meters of each solution should be used to obtain 400 cm^3 of a solution that is 9 percent acid?
1 solutions
Answer 115618 by scott8148(6628) on 2008-09-14 08:02:39 (Show Source):
You can put this solution on YOUR website!let x=cm^3 of 15%, so 400-x=cm^3 of 6%
(15%)(x)+(6%)(400-x)=(9%)(400) __ multiply by 100 to clear percentages
15x+2400-6x=3600 __ subtracting 2400 __ 9x=1200 dividing by 9 __ x=400/3
substituting __ 400-(400/3)=800/3
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Mixture_Word_Problems/156810: A chemist has two acid solutions.One contains 15 percent acid and the other contains 6 percent acid. How many cubic meters of each solution should be used to obtain 400 cm^3 of a solution that is 9 percent acid?
I need this now...please and thank you
1 solutions
Answer 115615 by scott8148(6628) on 2008-09-14 07:49:57 (Show Source):
You can put this solution on YOUR website!let x=cm^3 of 15%, so 400-x=cm^3 of 6%
(15%)(x)+(6%)(400-x)=(9%)(400) __ multiply by 100 to clear percentages
15x+2400-6x=3600 __ subtracting 2400 __ 9x=1200 dividing by 9 __ x=400/3
substituting __ 400-(400/3)=800/3
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Length-and-distance/156631: PLEASE PLEASE PLEASE HELP ME! IT'S DUE IN 5 HOURS ONLINE! THANKS!
A woman 5 ft tall is standing near a street lamp that is 12 ft tall, as shown in the figure. Find a function that models the length L of her shadow in terms of her distance d from the base of the lamp.
1 solutions
Answer 115463 by scott8148(6628) on 2008-09-13 05:16:14 (Show Source):
You can put this solution on YOUR website!using similar triangles __ the height of the lamp (12) is to the end of the shadow (d+L)
__ as the woman's height (5) is to the length of the shadow (L)
 __ "cross" multiplying __ 12L=5d+5L __ subtracting 5L __ 7L=5d __ dividing by 7 __ L=5d/7
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Travel_Word_Problems/156654: On a 255-mile trip, Gary traveled at an avg. apeed of 70mph, got a speeding ticket, and then traveled at 60mph for the remainder of the trip. If the entire trip took 4.5 hours and the speeding ticket stop took 30 minutes, how long did Gary speed before getting stopped? I tried using various formats of distance=rate x time and couldnt figure anything out to set up an equation.
1 solutions
Answer 115462 by scott8148(6628) on 2008-09-13 05:05:56 (Show Source):
You can put this solution on YOUR website!the driving time is 4.5h minus 30 min or 4h __ let s=speeding time, so 4-s is non-speeding
rt=d __ 70(s)+60(4-s)=255 __ 70s+240-60s=255 __ subtracting 240 __ 10s=15 __ s=1.5
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Rectangles/156656: A box with an open top is to be constructed from a rectangular piece of cardboard with dimensions 15 inches by 30 inches by cutting out equal squares of side x at each corner and then folding up the sides
So I have to find the volume when l=30-2x, w=15-2x and h=x
I tried to multiply everything out and got 4x^3-60x^2+450x... but got stuck... not sure wether doing that was right and if so how to continue - looked at taking x out, but still ended up in a big mess - could someone do a step by step breakdown please?
1 solutions
Answer 115461 by scott8148(6628) on 2008-09-13 04:55:49 (Show Source):
You can put this solution on YOUR website!it looks like you might have skipped a term...
FOILing l & w gives __ 450-60x-30x+4x^2 __ 4x^2-90x+450
distributing h gives __ 4x^3-90x^2+450x
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Linear_Equations_And_Systems_Word_Problems/156600: Please help, don't understand...thanks
A small publishing company is planning to publish a new book. The production costs will include one-time fixed costs (such as editing) and variable costs (such as printing). The one-time fixed costs will amount to $35,630. The variable costs will be $11.50 per book. The publisher will sell the finished product to bookstores at a price of $20.25 per book. How many books must the publisher print and sell so that the production costs will equal the money obtained from sales?
1 solutions
Answer 115389 by scott8148(6628) on 2008-09-12 13:43:26 (Show Source):
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Matrices-and-determiminant/156589: . A total of 700 tickets were sold for a musical. Senior citizen tickets sold for $15, children tickets sold for $20, and adult tickets sold for $25; the total earnings from ticket sales was $15,750. Five times more children tickets were sold than senior citizen tickets. How many tickets of each type were sold? Set up a system of three equations and three unknowns, use an augmented matrix to solve
I have most of the matrix figured out Here is what I got
[ 1 1 1 700 ]
[ 4 5 3 3,140 ] divided by 5
[ 0 5
I am struggling with the bottom half of the matrix. Specifically what numbers do I put in the last two columns. I am also struggling solving the matrix. Thanks for any help.
1 solutions
Answer 115387 by scott8148(6628) on 2008-09-12 13:31:18 (Show Source):
You can put this solution on YOUR website!"A total of 700 tickets were sold for a musical" __ s+c+a=700
"Senior citizen tickets sold for $15, children tickets sold for $20, and adult tickets sold for $25; the total earnings from ticket sales was $15,750" __ 15s+20c+25a=15750 __ 3s+4c+5a=3150
"Five times more children tickets were sold than senior citizen tickets" __ c=5s __ -5s+c+0a=0
[1 1 1 | 700]
[3 4 5 | 3150]
[-5 1 0 | 0]
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Human-and-algebraic-language/156029: The length of a rectangle is 7 inches less than 3 times its width. If the perimeter of the rectangle is 50 inches, what are its dimensions?
7-3x=50 is what I came up with but I do not believe that this is how to solve it but before I did it I just wanted some help I am taking a class online and can't ask the teacher.
Thank You
1 solutions
Answer 114994 by scott8148(6628) on 2008-09-10 11:32:47 (Show Source):
You can put this solution on YOUR website!"The length of a rectangle is 7 inches less than 3 times its width" __ L=3W-7
"the perimeter of the rectangle is 50 inches" __ 2L+2W=50
substituting __ 2(3W-7)+2W=50 __ 6W-14+2W=50 __ 8W=64 __ W=8
substituting __ L=3(8)-7 __ L=17
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Word_Problems_With_Coins/156004: Express the given quantity in terms of the indicated variable.
The value (in cents) of the change in a purse that contains twice as many nickels as pennies, eight more dimes than nickels, and as many quarters as dimes and nickels combined; p = number of pennies
What I tried:
n=nickels, d=dimes, q=quarters
n=2p; d=2p+8; q=2p+(2p+8)
p+2p+(2p+8)+[2p+(2p+8)]
9p+16=wrong answer :(
1 solutions
Answer 114906 by scott8148(6628) on 2008-09-09 20:57:43 (Show Source):
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test/155438: The level of thorium in a sample decreases by a factor of one-half every 4.2 million years. A meteorite is discovered to have only 7.6% of its original thorium remaining. How old is the meteorite?
1 solutions
Answer 114682 by scott8148(6628) on 2008-09-08 12:18:20 (Show Source):
You can put this solution on YOUR website!a formula for half-life is A=Ao(1/2)^(t/h)
A=current amount __ Ao=initial amount __ t=time __ h=half-life
.076=(.5)^(t/4.2x10^6) __ taking log __ log(.076)=(t/4.2x10^6)log(.5)
dividing by log(.5) __ [log(.076)]/[log(.5)]=t/4.2x10^6 __ multiplying by 4.2x10^6 __ {[log(.076)]/[log(.5)]}(4.2x10^6)=t
1.56x10^7=t
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Angles/155600: FK=2x
KJ=3x-6
HJ=5x-12
FH=2x=2
___ __
line FK is congruent to line HJ
Find the perimeter of FKJH
I wish I could draw the line segment & congruent lines/symbols but the computer will not allow it. I hope someone will understand.
I would appreciate any help & a break down of how you figure this out. My mind is a blank & I am trying to help my 13yo daughter
1 solutions
Answer 114681 by scott8148(6628) on 2008-09-08 11:56:31 (Show Source):
You can put this solution on YOUR website!"line FK is congruent to line HJ" __ 2x=5x-12 __ subtracting 2x and adding 12 __ 12=3x __ 4=x
"plug in" x to find the side lengths and add the sides together to find the perimeter
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Expressions-with-variables/155544: On the worksheet it shows the equation:
 The first thing i tried to do was get rid of the fraction by mutiplying by the LCD, which i figured would be (z)(2z)(5z)(z+1). however it ended up being a jumbled mess and left me very confused and now I have no idea what to do.
1 solutions
Answer 114568 by scott8148(6628) on 2008-09-07 18:43:45 (Show Source):
You can put this solution on YOUR website!you're using the right technique, but your LCD has too many z's - one is enough
LCD is (z) times (2), (already have the z), times (5), times (z+1)
(10(z+1))-(5(z+1))-(2(z+1))=10(10z) __ 10z+10-5z-5-2z-2=100z __ 3z+3=100z __ 3=97z __ 3/97=z
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logarithm/155503: The hydrogen ion concentration of a dilute solution of an acid is measured to be [H+] = 2.0x10-4. Determine the pH of the solution.
Im not really sure where to start to achieve the correct answer. If someone could show me the steps,and the correct answer,it would be greatly apperciated.
1 solutions
Answer 114559 by scott8148(6628) on 2008-09-07 18:30:30 (Show Source):
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Travel_Word_Problems/155510: In a walkathon to raise money for charity, Elisa walked a certain distance at 5 mi/h and then jogged twice that distance at 8 mi/h. Her total time walking and jogging was 2hr and 15min. How many miles long was the walkathon? The answer is 15mi but I cannot formulate the equation.
1 solutions
Answer 114542 by scott8148(6628) on 2008-09-07 16:26:10 (Show Source):
You can put this solution on YOUR website!r*t=d __ so t=d/r __ 2hr15min is 9/4 hr
"Elisa walked a certain distance at 5 mi/h" __ Tw=d/5
"jogged twice that distance at 8 mi/h" __ Tj=2d/8=d/4
the total time is Tw+Tj __ the total distance is 3d
d/5+d/4=9/4 __ multiplying by 20 __ 4d+5d=45 __ 9d=45 __ d=5 __ 3d=15
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