Problem
A washer and a dryer cost \( \$ 600 \) combined. The cost of the washer is three times the cost of the dryer. What is the cost of the dryer?
Solution
Step 1 ：Let the cost of the dryer be x. Then the cost of the washer is 3x.
Step 2 ：The combined cost is 600: x + 3x = 600
Step 3 ：Solve for x: 4x = 600, x = \( \frac{600}{4} \), x = 150
