1 |
(1+x)2 |
1 |
(1-x)2 |
A.S=2 |
B.S<2 |
C.S>2 |
D.S与2的大小与x的取值有关 |
1 |
(1+x)2 |
1 |
(1-x)2 |
(1-x)2+(1+x)2 |
(1+x)2(1-x)2 |
1-2x+x2+1+2x+x2 |
(1-x2)2 |
2+2x2 |
(1-x2)2 |
2+2x2 |
(1-x2)2 |
2+2x2-2+4x2-2x4 |
(1-x2)2 |
6x2-2x4 |
(1-x2)2 |
2x2(3-x2) |
(1-x2)2 |
2x2 |
(1-x2)2 |
2x2 |
(1-x2)2 |
4x |
x2-4 |
a |
x+2 |
b |
x-2 |
A.-6 | B.6 | C.-2 | D.2 |
2 |
a2+b2-c2 |
2 |
b2+c2-a2 |
2 |
c2+a2-b2 |
1 |
x |
1 |
y |
2x-3xy+2y |
x+2xy+y |
2xy |
x+y |
1 |
a2-b2 |
yz |
y+z |
1 |
a2 |
2xz |
x+z |
1 |
a2+b2 |
xyz |
xy+yz+zx |
1 |
10 |
x |
y |
2 |
7 |
x2-3xy+2y2 |
2x2-3xy+7y2 |
A.
| B.
| C.
| D.
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