已知1+2+3·······+31+32+33=17乘33,求1-3+2-6+3-9+········+31-93+32-96+3_数学解答

已知1+2+3·······+31+32+33=17乘33,求1-3+2-6+3-9+········+31-93+32-96+33-99的值,

人气：467 ℃　时间：2019-08-20 13:52:49

解答

1-3+2-6+3-9+········+31-93+32-96+33-99
=1+2+3+····+33-(3+6+9+····+99)
=1+2+3+····+33-3*(1+2+3+····+33)
=-2*(1+2+3+····+33)
=-2*17*33