## Algebra: A Combined Approach (4th Edition)

$3/2$
For this problem, you set the general formula of linear function $Y=aX+b$. Then plug (-2,6) and (0,9) into this formula. You get $6=-2a+b$ and $b=9$. Combine this two together, you get $6=-2a+9$, $a=3/2$