Question

1. Com as letras A , B e C vamos indicar esses polinômios A = x + 2; B = 2x - 5; C = 3x + 4
Agora , calcule

a) A - BC b) B - AC c) C - AB
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Answer 1

Resposta:

a) A - BC

$x + 2 - (2x - 5) \times (3x + 4) \\ x + 2 - (6 {x}^{2} + 8x - 15x - 20) \\ x + 2 - 6 {x}^{2} - 8x + 15x + 20 \\ - 6 {x}^{2} + 8x + 22 \times ( - 1) \\ 6 {x}^{2} - 8x - 22$

b) B - AC

$2x - 5 - (x + 2) \times (3x + 4) \\ 2x - 5 - (3 {x}^{2} + 4x + 6x + 8) \\ 2x - 5 - 3 {x}^{2} - 4x - 6x - 8 \\ - 3 {x}^{2} - 8x - 13 \times ( - 1) \\ 3 {x}^{2} + 8x + 13$

c) C - AB

$3x - 4 - (x + 2) \times (2x - 5) \\ 3x - 4 - (2 {x}^{2} - 5x + 4x - 10) \\ 3x - 4 - 2 {x}^{2} + 5x - 4x + 10 \\ - 2 {x}^{2} + 4x + 6 \times ( - 1) \\ 2 {x}^{2} - 4x - 6$