Question

初二分解因式

数学不好 见谅= =

1）(a-b)²-4a+4b+4

2）(-1/2)^2001+（1/2）^2000

3）(x+y)²-4(x+y-1)

4)-49x²+14x-1+y²

于是就这几道 帮帮忙 T T

Answer 1

(1)=(a-b)²-4(a-b)+4=(a-b-2)²
(2)=(-1/2)(1/2)^2000+(1/2)^2000=(1/2)^2000(-1/2+1)=(1/2)^2001
(3)=(x+y)^2-4(x+y)+4=(x+y-2)^2
(4)=y^2-(49x^2-14x+1)=y^2-(7x-1)^2=(y+7x-1)(y-7x+1)

Answer 2

（a-b)²-4a+4b+4=(a-b)²-4(a-b)+4=(a-b-2)²
(-1/2)^2001+（1/2）^2000 =(-1/2)(1/2)^2000+(1/2)^2000=(1/2)^2000(-1/2+1)=(1/2)^2001

(x+y)²-4(x+y-1)=(x+y)^2-4(x+y)+4=(x+y-2)^2

-49x²+14x-1+y²=y^2-(49x^2-14x+1)=y^2-(7x-1)^2=(y+7x-1)(y-7x+1)

Answer 3

(1)(a-b)²-4a+4b+4=(a-b-2)^2
(2)(-1/2)^2001+（1/2）^2000=(1/2)^2001
(3)(x+y)²-4(x+y-1)=(x+y-2)^2
(4)-49x²+14x-1+y²=(y-7x+1)(y+7x-1)