Question

The value of y varies directly with x. If x = 3, then y = 13. Show your work for finding the value of x when y = 39

Answer 1

x = 9 when y = 39

Explanation:

To solve this, we will use a proportion, since x varies directly with y, each will increase proportionately to the other.

3 / 13 = x / 39

Step 1: Cross Multiply

13x = 117

Step 2: Divide both sides by 13

13x / 13 = 117 / 13

x = 9

Step 3: Check

3 / 13 = 9 / 39

117 = 117 ✅

x = 9 when y = 39