Chapter 8 Rational Functions - 8.3 Graph General Rational Functions - 8.3 Exercises - Quiz for Lessons 8.1-8.3 - Page 571: 2

$$ 18$$

We plug in the given point to find the constant of variation. Since the equation will be for direct variation, we can then plug this in for $a$ in the equation $y=ax$. (Note, the y-intercept is 0). Hence, we find: $$-9=2a \\ a=-4.5 $$ When $x=-4$: $$y=-4.5\times -4 = 18$$