2x+2y |
x-y |
A.不变 | B.扩大2倍 | C.扩大4倍 | D.缩小2倍 |
2•2x+2•2y |
2x-2y |
2(2x+2y) |
2(x-y) |
2x+2y |
x-y |
a-b |
2a-b |
-(a-2b) |
2a-b |
-21x3y2 |
27x3y3z4 |
0.4x+2 |
0.5x-1 |
3a |
5xy |
() |
10axy |
6a3b2 |
8b3 |
3a3 |
() |
a+2 |
a2-4 |
1 |
() |
b+1 |
a+c |
() |
an+cn |
8a2c |
12a2b |
2c |
() |
2x |
x+3 |
() |
x2+3x |
x2-y2 |
(x+y)2 |
x-y |
() |
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