Question

Suppose y varies directly with x. write an equation relating x and y. y=7 when x=42

Answer 1

y =
`(1)/(6)` x

Explanation:

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

y = kx ← k is the constant of variation

To find k use the given condition that y = 7 when x = 42

k =
`(y)/(x)` =
`(7)/(42)` =
`(1)/(6)`

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