## Algebra 1: Common Core (15th Edition)

B. $y=-5x$ ; 75
We know direct variation has the equation y=kx. Thus, we plug in the points and solve for k: $y=kx \\\\ 10=-2k \\\\ k=-5$ We substitute k back in to get the equation: $y=-5x$ We now plug in x=-15: $y=(-5)(-15)=75$