Question 628788
Let x be the number of hours he anticipated working. Let y be the hourly wage he anticipated. He anticipated making $10 for the job.
xy=10
(x+8)(y-4)=10

y=10/x
(x+8)(10/x-4)=10

x(x+8)(10/x-4)=10x
(x+8)(10-4x)=10x
10x-4*x*x+80-32x=10x
-4*x*x-32x+80=0
*[invoke quadratic "x",-4,-32,80]
He anticipated working 2 hours.