1.x^2-81 (2).4/1^2-b^2 3.9(x-y)^2-25 4.(x^2-y)^2-(2y-2)^2 5.x^4-81 6.3x^6-3x^2 多项式因式分解

Question

求解答

Answer 1

1.x²-81
解:原式=(x+9)(x-9)
2.1/4×a²-b²
解:原式=1/4(a+b)(a-b)
3.9(x-y)²-25
解:原式=[3(x-y)+5][3(x-y)-5]
4.(x²-y)²-(2y-2)²
解:原式=[(x²-y)+(2y-2)][(x²-y)-(2y-2)]
=(x²-y+2y-2)(x²-y-2y+2)
=(x²+y-2)(x²-3y+2)
5.x^4-81
解:原式=(x²+9)(x²-9)
=(x²+9)(x+3)(x-3)
6.3x^6-3x²
解:原式=3x²(x^4-1)
=3x²(x²+1)(x²-1)
=3x²(x²+1)(x+1)(x-1)

Answer 2

1. x²-81
=x²-9²
=(x+9)(x-9)
2.1/4*a²-b²
=(1/2a)²-b²
=(1/2a-b)²
3.9(x-y)²-25
=[3(x-y)]²-5²
=[3(x-y)+5][3(x-y)-5]
=(3x-3y+5)(3x-3y-5)
4.(x²-y)²-(2y-2)²
=[(x²-y)+(2y-2)][(x²-y)-(2y-2)]
=(x²-y+2y-2)(x²-y-2y+2)
=(x²+y-2)(x²-3y+2)
5.x^4-81
=(x²)²-9²
=(x²+9)(x²-3²)
=(x²+9)(x+3)(x-3)
6.3x^6-3x²
=3x²(x^4-1)
=3x²[(x²)²-1²]
=3x²(x²+1)(x²-1)
=3x²(x²+1)(x+1)(x-1)来自：求助得到的回答本回答被提问者采纳

Answer 3

LZ其实只要知道
a^2-b^2=(a+b)(a-b)就都可以做了