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Question 205608This question is from textbook Algebra
: An experienced plumber maide $600 for working on a certain job. his apprentice, who makes $3 per hour less, also made 600. However, the apprentice worked 10h more than the plumber. How much does the plumber make per hour?
This question is from textbook Algebra
Answer by ptaylor(2198)   (Show Source):
You can put this solution on YOUR website! Let x=hourly wages of the plumber
Then x-3=hourly wages of his apprentice
Let y=number of hours the plumber worked
Then y+10 =number of hours the apprentice worked
Now we know that the amount made by the plumber=x*y=$600----eq1
We also know that amount made by the apprentice=(x-3)(y+10)=$600----eq2
So, our equation to solve is:
xy=(x-3)(y+10) expand right side using FOIL (First, Outer, Inner, Last)
xy=xy+10x-3y-30 subtract xy from each side; also add 3y and 30 to each side
xy-xy+3y+30=xy-xy+10x-3y+3y-30+30 collect like terms
3y+30=10x substitute y=600/x from eq1
3(600/x)+30=10x multiply each term by x
1800+30x=10x^2 divide each term by 10
x^2-3x-180=0 quadratic in standard form and it can be factored
(x-15)(x+12)=0
x=-12-------------------no good! wages are positive
and
x=$15---------------------plumber's hourly wages
x-3=15-3=$12------------apprencice's hourly wages
substitute x=15 into eq1
15y=600
y=40 hours worked by plumber
y+10=40+10=50--------------hours worked by apprentice
CK
50*12=40*15=600
600=600=600
Hope this helps---ptaylor
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