Question

A washer and a dryer cost $750 combined. The cost of the washer is two times the cost of the dryer. What is the cost of the dryer?

Answer 1

let the cost of the dryer = x
let the cost of the washer = y

x + y = 750
y = 2x

Substitute: 

x + 2x = 750
3x = 750
x = 250

250 + y = 750
y = 500

Therefore, the cost of the washer is $500 and the cost of the dryer is $250! :)
I hope this helps you! :D