Question

Someone help, please |

If y varies directly with x, and y = -20 and x = 5, what is x when y = -30?

Answer 1

x = 7.5

Explanation:

y is directly proportional to x

Formula:

y=k x (k represent as the proportion)

Substitute to given detail

When y=-20, x=5.

•At this point you need to solve k for the proportion.

-20=k(5)

5k=-20

k=-4 (Must be shown, youll be awarded mark(s) )

•Use k=-4 to complete the second equation.

When y= -30,

-30= (-4)x

-4x= 30

x= -(30/4)

x=-7.5

-7.5 Is the final answer