Question

PLEASE HELP

Suppose y varies directly with x, and y=10 when x= -3. What direct variation equation relates x and y ? What is the value of y when x= -1?

Answer 1

y =
`(10)/(3)`

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 condition y = 10 when x = - 3, thus

k =
`(y)/(x)` =
`(10)/(-3)` = -
`(10)/(3)`

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

When x = - 1, then

y = -
`(10)/(3)` × - 1 =
`(10)/(3)`