1²-2²+3²-4²+5²……-100²+101²
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1²-2²+3²-4²+5²……-100²+101²
1²-2²+3²-4²+5²……-100²+101²
1²-2²+3²-4²+5²……-100²+101²
1²-2²+3²-4²+5²……-100²+101²
=1+(3²-2²)+(5²-4²)+...+(101²-100²)
=1+2+3+4+5+...+100+101
=(1+101)×101÷2
=5151
1²-2²+3²-4²+5²……-100²+101²
=1²+(3+2)(3-2)+....+(101-100)(101+100)
=1+2+3+...+100+101
=5151
6080
原式=1+(3+2)×(3-2)+(5+4)×(5-4)+···+(101+100)×(101-100)
=1+2+3+4+5+···+100+101=5151
1²-2²+3²-4²+...+99²-100²+101²
=1²+(-2²+3²)+(-4²+5²)...(-98²+99²)+(-100²+101²)
=1²+(3²-2²)+(5²...
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1²-2²+3²-4²+...+99²-100²+101²
=1²+(-2²+3²)+(-4²+5²)...(-98²+99²)+(-100²+101²)
=1²+(3²-2²)+(5²-4²)...(99²-98²)+(101²-100²)
=1+(3+2)×(3-2)+(5+4)×(5-4)+......+ (101+100)×101-100)
=1+(3+2)+(5+4)+......+(101+100)
=1+2+3+4+5+......+100+101
=(1+101)×101÷2
=5151
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