1.a(a-b^2)
2.a-b
3.(2m+1/2n)^2
4.24ab
5.(a-3)^2+(b-1)^2
6.28
7.0
8.4a(5-a)
9.(6m+5n)(6m-5n)
10.y(y-1)^2
11.(x-4y)^2
12.(a+2)^4
13.(a+b)^2(a-b)^2
14.提出a-2 化简为(a-2)(a+2) 再变成a^2-4
15.a^2-2ab+b^2-b^2-10a+10b+25
=a^2-2ab+b^2-(b^2-10b+25)-10a+50
=(a-b)^2-(b-5)^2-10a+50
16.x^2+y^2=(x+y)^2-2xy
x^4+y^4=(x^2+y^2)^2-2x^2y^2
1.a(a-b^2)
2.a-b^2
3.(2m+1/2n)^2
4.24ab
5.a-3)^2+(b-1)^2
6.28
7.0
8.4a(5-a)
9.(6m+5n)(6m-5n)
10.y(y-1)^2
11.(x-4y)^2
12.(a+2)^4
13.(a^2-b^2)^2
14.=(a-2)(a^2+a+1)-(a-2)(a^2-1)
=(a-2)(2+a)
15.=a^2-2ab+1-1-10(a-b)+25
=(a-b)^2-10(a-b)+25-1
=(a-b-5)^2-1
16.x^2+y^2=x^2+2xy+y^2-2xy
=(x+y)^2-2xy
x^4+y^4=x^4+2x^2y^2+y^4-2x^2y^2
=(x^2+y^2)^2-2(xy)^2
=((x+y)^2-2xy)^2-2(xy)^2