Question

Efetue as multiplicações
A) (a²-b)(2a-5b)
B) (2×-3)(ײ-3×+5)
C) (×-3y+1)(2×+2y-6)

Answer 1

$A) \\ (a^2-b)(2a-5b)= \\ \\ =2a^2-5a^2b-2ab+5b^2 \\ \\ = 2a^2+5b^2-5a^2b-2ab \\ \\ \\ B) \\ (2x-3)(x^2-3x+5)= \\ \\ 2x^3-6x^2+10x-3x^2+9x-15= \\ \\ 2x^3-9x^2+19x-15 \\ \\ \\ C) \\ (x-3y+1)(2x+2y-6)= \\ \\ 2x^2+2xy-6x-6xy-6y^2+18y+2x+2y-6= \\ \\ 2x^2-6y^2-4xy-4x+20y-6$