I y varies directly with x and y = 16 when x = 4, then find the constant of variation, k.
Use k in the previous question to find the value of y when x = 7.
They vary directly so y = kx (if they varied INdirectly it would be y = k/x)
y = kx divide both sides by x
y/x = k Now sub in the values given to find k
16/4 = k = 4
Second part: y = kx y = 4x y = 4(7) = 28 when x = 7