Question

A washer and a dryer cost $770 combined. The washer costs $70 more than the dryer. What is the cost of the dryer?

Answer 1

Let w = washer and d = dryer:

w + d = $770,
but w = d + 70, replace w with d+70
(d+70) + d = 770
2d + 70 =770
2d = 770 -70 = 700
and d=$350, then w=350+70 = 420