Question

Please help me with this problem..

Answer 1

y = 6

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 = 3 when x = 9, then

k =
`(y)/(x)` =
`(3)/(9)` =
`(1)/(3)`, thus

y =
`(1)/(3)` x ← equation of variation

When x = 18, then

y =
`(1)/(3)` × 18 =
`(18)/(3)` = 6