Answer:
y = 0.75x
Step-by-step explanation:
Given y varies directly as x then the equation relating them is
y = kx ← k is the constant of variation
To find k substitute either of the 2 points into the equation
Using (12, 9 ), then
k = [tex]\frac{y}{x}[/tex] = [tex]\frac{9}{12}[/tex] = 0.75, so
y = 0.75x ← equation of variation
