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Question 188493This question is from textbook
: A student did a word processing job for $24. It took him 1 hour longer than he expected, and therefore he earned $4 per hour less than he anticipated. How long did he expect that it would take to do the job?
thanks
This question is from textbook
Answer by Mathtut(3670)   (Show Source):
You can put this solution on YOUR website! let x =hours expected to do job let A=earnings per hour
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24/x=A.......eq 1
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24/x+1=A-4..eq 2
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substitute A's value from eq 1 into eq 2
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24/(x+1)=(24/x)-4
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24/(x+1)=(24-4x)/x
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24x=(x+1)(24-4x).......cross multiplied
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 divided all terms by 4
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x=2 and -3.....we cant have negative hours
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so x=2 hours of expected work.......but it took 3 hours
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| Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc) |
Quadratic equation  (in our case  ) has the following solutons:
For these solutions to exist, the discriminant  should not be a negative number.
First, we need to compute the discriminant :  .
Discriminant d=400 is greater than zero. That means that there are two solutions:  .
Quadratic expression  can be factored:
Again, the answer is: 2, -3.
Here's your graph:
 |
| Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc) |
Quadratic equation (in our case ) has the following solutons:
For these solutions to exist, the discriminant should not be a negative number.
First, we need to compute the discriminant : .
Discriminant d=400 is greater than zero. That means that there are two solutions: .
Quadratic expression can be factored:
Again, the answer is: 2, -3.
Here's your graph:
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