100 |
n=1 |
50 |
n=1 |
2013 |
n=1 |
1 |
n(n+1) |
2013 |
n=1 |
1 |
n(n+1) |
1 |
1×2 |
1 |
2×3 |
1 |
2013×2014 |
1 |
2 |
1 |
2 |
1 |
3 |
1 |
2013 |
1 |
2014 |
1 |
2014 |
2013 |
2014 |
2013 |
2014 |
2xy+4y |
2xy2 |
2x-4y |
2xy2 |
1 |
x-2 |
1 |
x2-5x+6 |
A.
| B.
| ||||||||||||
C.
| D.
|
x2 |
x+y |
y2 |
x+y |
A.-x-y | B.y-x | C.x-y | D.x+y |
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