Question

5. Descompuneți în factori:
a)x^3 + 2x^2 - 16(x + 2)
b)x^3 + 5x^2 - 9(x + 5)
d)16(x - 5)^2 - 9(2x - 3)^2

Answer 1

$a) {x}^{2} (x + 2) - 16(x + 2) = (x + 2)( {x}^{2} - 16) = (x + 2)(x - 4)(x + 4)$

$b) {x}^{2} (x + 5) - 9(x + 5) = (x + 5)( {x}^{2} - 9) = (x + 5)(x - 3)(x + 3)$

$d)(4(x - 5) - 3(2x - 3)) \times (4(x - 5) + 3(2x - 3)) = (4x - 20 - 6x + 9)(4x - 20 + 6x - 9) = ( - 2x - 11)(10x - 29)$