Question

初中数学因式分解题

1.(x-y)²-x²
2.4(x-y)²-4z(x-y)+z²
3.(1-1/2²)(1-1/3²)......(1-1/10²)
4.3X²+75
4.27y²+18y+3

Answer 1

1.(x-y)²-x²
=(x-y-x)(x-y+x)
=-y(2x-y)

2.4(x-y)²-4z(x-y)+z²
=(2x-2y-z)²
3.(1-1/2²)(1-1/3²)......(1-1/10²).
=(1-1/2)(1+1/2)(1-1/3)(1+1/3)(1-1/4)(1+1/4).......(1-1/10)(1+1/10)
=1/2×3/2×2/3×4/3×3/4×5/3....10/9×9/10×11/10
=11/20
4 .3X²+75
=3(x²+25)

4.27y²+18y+3
=3(9y²+6y+1)
=3(3y+1)²

Answer 2

1、（x-y+x）（x-y-x） =x(2x-y)
2、(2x-2y+z)的平方

追问

其他的来。

Answer 3

1, (x-y+x)(x-y-x)=-(2x-y)y
2. (2x-2y-z)^2
3, (1+1/2)(1-1/2)(1+1/3)(1-1/3)....(1+1/10)(1-1/10)
4 , 3(x^2+25)
5, 3(9y^2+6y+1)=3(3y+1)^2