## Algebra 1

$y=2.5x;30$
start with the function form of a direct variation $y=kx$ now substitute 3 for x and $7\frac{1}{2}$ for y (we will use 7.5) $7.5=k(2)$ divide both sides by 3 and solve for $k$ $\frac{7.5}{3}=\frac{k(3)}{3}$ $k=2.5$ write an equation and substitute 2.5 for k. $y=2.5x$ Now solve for x=12 $y=2.5(12)$ $y=30$