Mrs. Atkins pays $ 1,800 for a new refrigerator washer, and dryer.
The refregerator cost $ 250 more
than the washer. The dryer costs
half as much as the washer.
How much does the washer cost?
The was her cost:

A: $620

Explanation:
first set your variables:
refrigerator: r
washer: w
dryer:d

next create your equation:
1800= r+w+d

now use what you know to solve the problem. you know how much the refrigerator and dryer cost, so create an equation based off that knowledge.

r = 250 + w
d = 1/2w

now substitute those equations for the variables:
1800 = 250 + w + 1/2w + w
(r) (d)

combine like terms:
1800 = 250 + 2w + 1/2w

1800 = 250 + 2.5w

subtract 250 from both sides:
1550 = 2.5w

divide by 2.5:
w= 620

if you want to check, plug in the w value and see if everything equals 1800:
1800 = 250 + 620 + 1/2(620) + 620
1800 = 870 + 310 + 620
1800 = 1800

it is correct, hope this helps :))