Question

因式分解，急！！！！！！！！！！！！

-2a^2+2ab-6a
x^3y-10x^2y^2+25xy^3
b^2-4a^2+4a-1
(x-3)(x=5)+x^2-9
4b^2c^2-(b62+c^2-a^2)^2

Answer 1

-2a^2+2ab-6a
=-2a（a-b+3)

x^3y-10x^2y^2+25xy^3
=xy(x²-10xy+25y²)
=xy(x-5y)²

b^2-4a^2+4a-1
=b²-(4a²-4a+1)
=b²-(2a-1)²
=[b+(2a-1)][b-(2a-1)]
=(b+2a-1)(b-2a+1)

(x-3)(x+5)+x^2-9
=x²-2x-15+x²-9
=2x²-2x-24
=2(x²-x-12)
=2(x+3)(x-4)

4b^2c^2-(b2+c^2-a^2)^2
=[2bc+(b²+c²-a²)][2bc-(b²+c²-a²)]
=[(b²+2bc+c²)-a²][a²-(b²-2bc+c²)]
=[(b+c)²-a²][a²-(b-c)²]
=(b+c+a)(b+c-a)(a+b-c)(a-b+c)

Answer 2

(x-3)(x=5)+x^2-9是(x-3)(x-5)+x^2-9吗？
我可以待会发图片

追问

是（x-3)(x+5)+x^2-9