题目内容
-2x+2y=()-2(x-y).
( )
把
A.x2-2xy+y2-2x+2y=(x2+y2)-(2xy+2x-2y)
B.x2-2xy+y2-2x+2y=(x2-2xy+y2)-(2x-2y)
C.x2-2xy+y2-2x+2y=(x2+y2)-(-2xy-2x+2y)
D.x2-2xy+y2-2x+2y=(x2-2xy+y2)-(-2x+2y)
用含x的代数式表示y
①3x+y=1
②2x-2y=7
③x+=6
④--1=0
分解因式:-2x-2y=________.
下列运算正确的是【 】
A.(-2x2)3=-6x6 B.x4÷x2=x2
C.2x+2y=4xy D.(y+x)(-y+x)=y2-x2