He can make 5 sculptures.
We divide the amount of clay, 14 pounds, by the amount it takes to make one sculpture, 2 4/5 pounds:
14 ÷ 2/45 = 14 ÷ 14/5 = 14/1 ÷14/5 = 14/1 × 5/14 = 70/14 = 5
Y = x - 1
because the gradient is 1 and the y-intercept is -1
Price increase is $ 22-20 =$2 so the percent increase is 2/20 x 100= 10%