y = kx is the formula for direct variation
8 = k*20
divide by 20
8/20 =k
divide by 4
2/5 =k
y = 2/5 x
formula: y = 2/5x
b) y=2/5x
y = 2/5 *7
y = 14/5
or as a mixed number 2 4/5
