pomocy! wyrażenia algebraiczne. podpunkt c,d,e

c) a^2 - 2a + 1 - 5 = (-4)^2 - 2 * (-4) + 1 - 5 = 16 + 8 + 1 - 5 = 25 - 5 = 20
d) (x + 3)(x - 2) = (5 + 3)(5 - 2) = 8 * 3 =24
e) a - 2b = 2 - 2 * (-2) = 2 + 4 = 6