Question

Va rog e urgent!!!5. Descompuneţi în factori:
a) x³ + 2x²-16(x + 2);
d) 16(x + 5)²-9(2x - 3)²;
g) 4x²-9-(2x + 3);
b) x +5r – 9(x +5);
e) 25x² - 4(x²+2x-3)²;
h) 16x-25-3(4x + 5).
c) 36(x-2)²-25(x + 1)²;
f) 9(2x-5)2-4(4x - 3)²

Answer 1

Răspuns:

a)

x^2•(x+2) - 16(x+2) = (x+2)(x^2 - 16) = (x+2)(x-4)(x+4)

d)

(4x+20-6x+9)(4x+20+6x-9) = (29-2x)(11+10x)

g)

(2x-3)(2x+3) - (2x+3) = (2x+3)(2x-3-1) = 2(x-2)(2x+3)

b)

(x+5)(1-9) = -8(x+5) Dacă e scria corect...

e)

x^2 + 2x - 3 = (x-1)(x+3)

[5x - 2(x-1)(x+3)][5x + 2(x-1)(x+3)] =

(5x - 2x^2 - 4x + 6)(5x + 2x^2 + 4x - 6) = (-2x^2 + x + 6)(2x^2 + 9x - 6)

h)

16x - 25 - 12x - 15 = 4x - 40 = 4(x - 10)

c) (6x - 12 - 5x - 5)(6x - 12 + 5x + 5) = (x - 17)(11x - 7)

f)

(6x - 15 - 8x + 6)(6x - 15 + 8x - 6) = (-2x - 9)(14x - 21) = -3(2x + 9)(2x - 3)