x equals number of hours
company 1: 376+12x
company 2: 280+15x
set them equal to each other to get the amount of hours
376+12x=280+15x >>> than subtract 280 from both sides
-280 -280 that equals
96+12x=15x than subtract 12x from both sides
-12x -12x
96=3x than divide the whole equation by 3
32=x
(a) 32 hours
and to get part b just plug the 32 into one of the equations
376+12(32)
376+384
760
(b) $760
if you plug it into the other equation you get the same answer so that means that the answer is correct
I hope this helps
