Answer:
y = 6
Step-by-step explanation:
given x and y vary directly , then the equation relating them is
y = kx ← k is the constant of variation
To find k, substitute y = 9, x = 12 into the equation
9 = 12k ( divide both sides by 12 )
[tex]\frac{9}{12}[/tex] = k , then
k = [tex]\frac{3}{4}[/tex] = 0.75
y = 0.75x ← equation of variation
when x = 8 , then
y = 0.75 × 8 = 6