Question

The values of x and y vary directly

and one pair of values are given.
Write an equation that relates x
and y. Simplify completely.
x = -4, y = 6
y=
[?]
y =
1

Answer 1

y = -
`(3)/(2)` x

Explanation:

Given that x and y vary directly then the equation relating them is

y = kx ← k is the constant of variation

To find k use the condition x = - 4, y = 6, thus

k =
`(y)/(x)` =
`(6)/(-4)` = -
`(3)/(2)`

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