help

[Guest]

The Variables x and y vary directly. Write an equation that relates the variables. then find y when x=8.

1. x=-6, y=15

i dont understand how to do these


thank you

 

[Gene]

As you may have heard the direct variation equation is
y=kx or
k=y/x = 15/-6 = -2.5
So the equation is
y=-2.5x