Question

1) Aplicando as regras dos produtos notáveis,
desenvolva:
a) (x - 12). (x + 12) =
b) (x - 7)2 =
c) (x + 3y).(x - 3y) =
d) (x + 3)2 =

Answer 1

a) (x - 12) . (x + 12) -> x . x + 12 . x - 12 . x - 12 . 12 -> x^2 + 12x - 12x - 144 = x^2 - 144

b) (x - 7)^2 -> (x - 7) . (x - 7) -> x . x - 7 . x - 7 . x - 7 . (-7) = x^2 - 14x + 49

c) (x + 3y) . (x - 3y) -> x . x - x . 3y + x . 3y - 3y . 3y -> x^2 - 3xy + 3xy - 9y^2 = x^2 - 9y^2

d) (x + 3)^2 -> (x + 3) . (x + 3) -> x . x + 3 . x + 3 . x + 3 . 3 -> x^2 + 3x + 3x + 9 = x^2 + 6x + 9