Explications étape par étape:

a = 6(x -2)

b = (7(y + 3)

c = a(a + 8)

d = 9(m -2)

e = 3(-b + 2)

f = (5(x + 1)

g = c(2c - 3)

h = 7(y - 1)

i = 3(-a + 1)

j = z(z + 1)

k = 7(x - 2)

l = 3a(a + 1)

m = t(2t - 3)

n = 5x(-x + 5)

o = 7(7a - 3d)

p = 2(6t² - t + 6)

q = 3(-11z + 4m)

r = 4d(d + 5)