Question

Suppose y varies directly with x. Write a direct variation equation to relate x and y if y = 10 when x = 2

Answer 1

y = 5x

Explanation:

Given that y varies directly with x then the equation relating them is

y = kx ← k is the constant of variation

To find k use the condition y = 10 when x = 2

10 = 2k ( divide both sides by 2 )

5 = k

y = 5x ← equation of variation

Answer 2

y=5x and y=40 when x=8