Question

Suppose that y varies directly with x, and y=4 when x=16.

Answer 1

see explanation

Explanation:

(a)

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 = 4 when x = 16 , so

4 = 16k ( divide both sides by 16 )

`(4)/(16)` = k , then k =
`(1)/(4)`

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

(b)

when x = 3 , then substituting into the equation

y =
`(1)/(4)` × 3 =
`(3)/(4)`