If y = 22 when x = 8, find y when x = -16

Question

"Suppose y varies directly as x. write a direct variation equation that relates x and y. then solve."  Thank you :)

Answer 1

If y varies directly as x then we can write y=kx where k is a constant, which we can find plugging in x and y values:

22=8k so k=22/8=11/4; therefore y=11x/4.

We can use this equation to find the y value when x=-16:

y=11(-16)/4=11×(-4)=-44.