题目内容
(1+
)+(2+
×2)+(3+
×3)+…+(10+
×10)=______.
| 7 |
| 11 |
| 7 |
| 11 |
| 7 |
| 11 |
| 7 |
| 11 |
(1+
)+(2+
×2)+(3+
×3)+…+(10+
×10),
=(1+2+3+…+10)+
×(1+2+3+…+10),
=(1+2+3+…+10)×(1+
),
=55×
,
=90.
| 7 |
| 11 |
| 7 |
| 11 |
| 7 |
| 11 |
| 7 |
| 11 |
=(1+2+3+…+10)+
| 7 |
| 11 |
=(1+2+3+…+10)×(1+
| 7 |
| 11 |
=55×
| 18 |
| 11 |
=90.
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