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Polynomials-and-rational-expressions/585091: For r(x) = 10x^2-19x-5 find all values of r(a)=-11.
My problem with this is i cannot factorize it. I have gotten to this point:
r(a)=10a^2-19a-5
10a^2-19a-5-11
10a^2-19a+6=0.
When i multiply 10*-5 i get - 50, i cannot find factors in that for -19
I also tried 10*6. The factors i get -15+-4. But when i work the equation and get the answers and plug them into the first problem it does not equal to -11. Please help me. Thank you
1 solutions
Answer 373093 by richwmiller(9135)   on 2012-03-10 12:35:36 (Show Source):
You can put this solution on YOUR website!Not 10a^2-19a-5-11 but
10a^2-19a-5=-11
10a^2-19a-5+11=0
10a^2-19a+6=0
(2x-3)*(5x-2)=0
(2x-3)=0
2x=3
x=3/2
(5x-2)=0
5x=2
x=2/5
Both work.
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Travel_Word_Problems/584996: Ann can jog to work in 2/3 of an hour. When she rides her bike, it takes her 1/4 of an hour. If she rides 11 miles per hour faster than she jogs, how far away is her work?
Do not do any rounding.
1 solutions
Answer 373080 by richwmiller(9135) on 2012-03-10 11:25:51 (Show Source):
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Word_Problems_With_Coins/585059: Pam has a coin purse consisting of 56 coins, a mixture of dimes and quarters. The total value of the coins inside the coin purse is $8.15. How many of each type of coin does Pam have?(Hint:think of coin values!)
It must be a system.
1 solutions
Answer 373070 by richwmiller(9135) on 2012-03-10 11:14:16 (Show Source):
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Permutations/585050: Here is a word problem:
In order to guarantee all emergency phone calls are received, the phone company wants all phone numbers with a 9 followed by two 1's to be routed to the 9-1-1 emergency help center. This will ensure that any real emergency victims will still get the help they require regardless of whether or not they accidentally hit extra keys. The digits 9-1-1 do not need to be consecutive but they do need to be in that order (e.g. 197-8141 and 009-1211) would get routed to 9-1-1, but 514-9313 would not, since the 9 is only followed by a single one. How many 7-digit phone numbers would not be able to be used since they would be routed to the 9-1-1 emergency center? Assume all 7-digit phone numbers are available from 000-0000 to 999-9999.
1 solutions
Answer 373067 by richwmiller(9135) on 2012-03-10 11:07:27 (Show Source):
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Probability-and-statistics/585056: Hello here is my question for my assisnment.
Let's say you got a 78 on a Stats exam. Suppose the class mean was M = 55 and
the variance was s2 =16. Suppose you also got a 98 on a Theatre exam where the
class mean was M = 90 and the standard deviation was s = 4. Use z-scores to
determine on which exam you were furthest above the mean, stats or theatre.
Remember to show your calculations.
I am not sure how to go about solving this problem. I was thinking that you would have to start out by using the equation z= x-u/standard dev But would you do that equation twice for each exam both the theatre and the stats. I am very confused. Please help. Thank You
1 solutions
Answer 373066 by richwmiller(9135) on 2012-03-10 11:05:18 (Show Source):
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Polygons/585076: what would the perimeter of a pentagon with each side being -3x+9 inches.... im stumped and cant remember how to do this for the life of me
1 solutions
Answer 373064 by richwmiller(9135) on 2012-03-10 10:58:29 (Show Source):
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Rational-functions/585060: identify the points of discontinuity: hole and vertical asymptote
f(x)= 1/3x^2+3x-18
f(x)= x-2/x-4
f(x)= x^3-x^2-6x/-3x^2-3x+18
f(x)= x^2+x-6/-4x^2-16x-12
1 solutions
Answer 373061 by richwmiller(9135) on 2012-03-10 10:56:43 (Show Source):
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Miscellaneous_Word_Problems/585061: The office jet printer can copy Lisa's dissertation in 20 min. The Laser jet printer can copy the same document in 12 min. If the two machines work together, how long would they take to copy the dissertation?
1 solutions
Answer 373059 by richwmiller(9135) on 2012-03-10 10:52:03 (Show Source):
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Travel_Word_Problems/585000: Two cars leave towns 800 kilometers apart at the same time and travel toward each other. One car's rate is 12 kilometers per hour more that the other's. If they meet in 5 hours, what is the rate of the faster car?
Do not do any rounding.
1 solutions
Answer 373043 by richwmiller(9135) on 2012-03-10 07:22:28 (Show Source):
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Proportions/585022: A fraction has a reduced ratio of 2:5. When 5 is added to both the numerator and the denominator, the new reduced ratio is 1:2. Find the original fraction.
1 solutions
Answer 373042 by richwmiller(9135) on 2012-03-10 07:17:43 (Show Source):
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Rational-functions/585030: A telephone company offers you an opportunity to sell prepaid, 30 minute long-distance phone cards. You will have to pay the company a one-time set-up fee of $200. Each phone card will cost you $5.70. How many cards would you have to sell before your average total cost per card falls to $8?
1 solutions
Answer 373041 by richwmiller(9135) on 2012-03-10 07:14:49 (Show Source):
You can put this solution on YOUR website!y=mx+b
y=mx+200
y=5.70x+200
8x=5.7x+200
2.3x=200
x=86.95
so you have to sell 87 cards to get the average cost down to 8 dollars each
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Mixture_Word_Problems/585005: Hannah is mixing two types of Easter candy. The chocolates cost $5 a pound, and the caramels cost $4 a pound. If she creates 8 pounds worth $4.25 a pound, how much of the chocolate did she use?
1 solutions
Answer 373039 by richwmiller(9135) on 2012-03-10 07:04:52 (Show Source):
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Probability-and-statistics/584895: Taylor made up a tournament test. Taylor’s test consists of true/false questions and fill-in-the-blank questions. There are 24 questions on the test. If the true/false questions are worth three points each and the fill-in-the-blank questions are worth seven points each for a total of 100 points, how many of the questions are fill-in-the blank questions?
1 solutions
Answer 372953 by richwmiller(9135) on 2012-03-09 15:04:38 (Show Source):
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Mixture_Word_Problems/584871: eighty percent of G is 352. What is G?
If G = 3/H + 4, then H =.
If P/ 5 = Q, then P/10 =.
what number is halfway between 2/9 and 4/5?
how is 4,345,000,000 written in scientific notation?
1 solutions
Answer 372952 by richwmiller(9135) on 2012-03-09 15:01:16 (Show Source):
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