Question

A washer and dryer cost $869 combined. The washer cost $81 less than the dryer. What is the cost of the dryer?

Answer 1

Let's assume the price of the washer is w and the price of the dryer is d.
w + d = 869
d - 81 = w
To find the cost of the dryer, we just need to substitute it for w in the first equation:
(d - 81) + d = 869
2d - 81 = 869
2d = 950
d = 475
The dryer is $475

Answer 2

w+d=869
w=d-81
plug in
(d-81)+d=869
2d-81=869
+81 both sides
2d=950
÷2 both sides
d=475
dryer cost $475

let's check w=475-81
w=394
475+394=869
869=869
the solution is true :)