初一 数学 因式分解的简单应用 请详细解答,谢谢! (21 18:50:51)

1. （x2+2xy+y2)/(x+y) =(x+y)^2/(x+y)=x+y

2. [(a-b)2+2(b-a)]/(a-b) = (a-b)-2

3. (ab2+a2b)/(a+b)=ab(b+a)/(a+b)=ab

4. (x2-49)/(7-x) =(x-7)(x+7)/(7-x)=-(x+7)

5. (4mn3+6m3n)/(2n2+3m2)=2mn(2n^2+3m^2)/(2n^2+3m^2)=2mn

6. [(2a-1)2-(3a-1)2]/(5a-2)=[(2a-1+3a-1)(2a-1-3a+1)]/(5a-2)=-a

1.
（x^2+2xy+y^2)/(x+y)
=(x+y)^2/(x+y)
=x+y

2.
[(a-b)^2+2(b-a)]/(a-b)
=[(a-b)^2-2(a-b)]/(a-b)
=(a-b)[(a-b)-2]/(a-b)
=(a-b)-2
=a-b-2

3.
(ab^2+a^2b)/(a+b)
=ab(b+a)/(a+b)
=ab

4.
(x^2-49)/(7-x)
=[(x-7)(x+7)]/(7-x)
=[(x-7)(x+7)]/[-(x-7)]
=-(x+7)
=-x-7

5.
(4mn^3+6m^3n)/(2n^2+3m^2)
=mn(4n^2+6m^2)/(2n^2+3m^2)
=2mn(2n^2+3m^2)/(2n^2+3m^2)
=2mn

6.
[(2a-1)^2-(3a-1)^2]/(5a-2)
=[(2a-1)-(3a-1)][(2a-1)+(3a-1)]/(5a-2)
=[(2a-1-3a+1)(2a-1+3a-1)]/(5a-2)
=[(-a