Question

Suppose y varies directly with x. Write a direct variation equation that relates x and y. Then find the value of y when x=16...

y=7 when x=2

Answer 1

Explanation:

y = kx, where k is a real constant.

When x = 2, y = 7.

=> (7) = k(2), 2k = 7, k = 3.5.

Therefore when x = 16,

y = (3.5)(16) = 56.

The value of y is 56 when x is 16.

Answer 2

The formula for direct variation is y = kx

Using the known x and y solve for k:

7 = k2

Divide both sides by 2:

k =7/2 = 3.5

Now solve for y when x = 16:

y = 3.5(16)

y = 56