A = 3(2x - 6) - (3 - 5x)
A = 6x - 18 - 3 + 5x
A = 11x - 21
B = (5 - 2y) - (-3y + 7)
B = 5 - 2y + 3y - 7
B = y - 2
C = 4(6 + z) + (z - 3)(2 - z)
C = 24 + 4z + 2z - z² - 6 + 3z
C = -z² + 9z + 18
D = (2t - 5)(3t + 2) - (t² + 6)
D = 6t² + 4t - 15t - 10 - t² - 6
D = 5t² - 11t - 16
