Question

35. Calcule.
a) (a - 7)(a - 9)
b) (6 - 5x)(1 - 2x)
c) (-x + 5)(x + 2)
d) (x2 + x - 1)(x - 1)​

Answer 1

Resposta:

a) (a - 7)(a - 9) =a²-9a-7a+72 =a²-16a+72

b) (6 - 5x)(1 - 2x) =6-12x-5x+10x² =6-17x+10x²

c) (-x + 5)(x + 2) =-x²-2x+5x+10 =-x²+3x+10

d) (x² + x - 1)(x - 1)​  =x³-x²+x²-x-x+1 =x³-2x+1