Question

сократить$1) frac{(a-3)^2-49}{24-2a-a^2} 2) frac{5x^3-120x^3}{5x^2-20y^2} 3) frac{x^3-y^3}{(x-y)(x^2+xy+y^2)}$

Answer 1

1
a²+2a-24=0
a1+a²=-2 U a1*a2=-24⇒a1=-6 U a2=4
(a-3-7)(a-3+7)/(a+6)(4-a)=(a-10)(a+4)/(a+6)(4-a)
не сокращается
2
-115/x³/5(x²-4y²)=-23x³/(x²-4y²)=23x³/(4y²-x²)
3
(x-y)(x²+xy+y²)=x³-y³
(x³-y³)/(x³-y³)=1