反馈练习.doc

文档介绍：A.(x-y)2=(y-x)2 B.(x+6)(x-6)=x2-6C.(x+y)2=x2+y2 (x-2)+x(2-x)=(x-2)(x-6)()+x2=2x4 ·a3=a5C.(-2x2)4=16x6 D.(x+3y)(x-3y)=x2-()A.(-4x)·(2x2+3x-1)=-8x3-12x2-4xB.(x+y)(x2+y2)=x3+y3C.(-4a-1)(4a-1)=1-16a2D.(x-2y)2=x2-2xy+4y24.(x+2)(x-2)(x2+4)的计算结果是()+16 B.-x4-16 -16 -,能整除代数式(n+3)(n-3)-(n+2)(n-2)的整数是() .()(5a+1)=1-25a2,(2x-3)=4x2-9(-2a2-5b)()=4a4-25b27.(a+b)2=(a-b)2+a2+b2=[(a+b)2+(a-b)2](),a2+b2=(a+b)2+,a2+b2=(a-b)2+..(1)(a+b)2-(a-b)2(2)(3x-4y)2-(3x+y)2;(3)(2x+3y)2-(4x-9y)(4x+9y)+(2x-3y)2;(2a+2b+1)(2a+2b-1)=63,求a+(a+b)2=60,(a-b)2=80,求a2+b2及ab的值.