Question

Suppose y varies with x. Write a direct variation equation that relates x and y. Then find the value of y when x=10

Answer 1

• y = 1.5x
• y = 15 when x = 10

Explanation:

A direct variation equation is of the form ...

y = kx

for some constant k. We can arbitrarily choose k=1.5, so our equation is ...

y = 1.5x

For x=10, the value of y is ...

y = 1.5·10 = 15