Question

分解因式(2n+1)²-(2n-1)²

Answer 1

(2n+1)²-(2n-1)²
=(2n+1+2n-1)(2n+1-2n+1)
=4n*2
=8n

不懂可追问，有帮助请采纳，谢谢！

Answer 2

(2n+1)²-(2n-1)²
=((2n+1)+(2n-1))((2n+1)-(2n-1))
=(2n+1+2n-1)(2n+1-2n+1)
=4n*2
=8n

追问

ab-a-b+1咋分解

追答

a²-b²=(a+b)(a-b)

(a+b)(a-b)=a*a+ab-ab-b*b=a²-b²

追问

大哥我说的是这个ab-a-b+1，不是a²-b²，从哪儿来的

追答

a²-b²=(a+b)(a-b)

a=2n+1
b=2n-1