9y²-12xy-45x²=(3y)²-2*3y*2x+4x²-4x²-45x²=(3y-2x)²-49x²=(3y-2y)²-(7x)²=
=(3y-2x-7x)(3y-2x+7x)=(3y-9x)(3y+5x).
(5p^4q^2)^3/(10pq)^2=125p^12q^6/100p^2q^2=5p^10q^4/4.
X^2 (x + 2) - 9(x + 2) = 0
(x + 2)(x^2 - 9) = 0
x + 2 = 0
x₁ = - 2
x^2 - 9 = 0
x^2 = 9
x₂ = - √9 = - 3
x₃ = √9 = 3
Ответ:
- 3; 3 ; - 2
9х+13= 7х + 5
9х-7х=5-13
2х=-8
х=-4