Question

In a direct variation, y=18 when x=9. Write a direct variation equation that shows the relationship between x and y

Answer 1

y = 2x

Explanation:

since x and y vary directly then the equation is

y = kx ← k is the constant of variation

to find k use the given condition y = 18 when x = 9

k =
`(y)/(x)` =
`(18)/(9)` = 2, hence

y = 2x ← is the equation relating x and y