1-2²+3²-4²+5²-6²+.+99²-100²+101²
问题描述:
1-2²+3²-4²+5²-6²+.+99²-100²+101²
请计算
答
1²-2²+3²-4²+5²-6²+…+99²-100²+101²
=(1-2)(1+2)+(3-4)(3+4)+.(99-100)(99+100)+101²
=-(1+2+3+4.+99+100)+10201
=-5050+10201
=5151