The square has a side length of 9.
The area of the full square would be 9^2 = 9 x 9 = 81 square cm.
The area of the triangle is 1/2 x 4 x 3 = 6 square cm.
The area of the shape = 81 -6 = 75 square cm.
add them together then divide by 5
81 +86 +81 +76 +71 = 395
395/5 = 79
your average was 79
To find the x intercept set y = 0
x^2 + x - 2 =0
(x+2)(x-1) = 0
x = -2 , x = 1