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计算a+(a+d)+(a+2d)+``````+(a+99d)前面有例题:1+2+3+``````+100=(1+100)+(2+99)+``````+(50+51)=101乘以50=5050

题目详情
计算a+(a+d)+(a+2d)+``````+(a+99d)
前面有例题:
1+2+3+``````+100
=(1+100)+(2+99)+``````+(50+51)
=101乘以50=5050
▼优质解答
答案和解析
a+(a+d)+(a+2d)+``````+(a+99d)=100a+(d+2d+…+99d)=100a+(1+2+3+…+100)d-100d=100a+5050d-100d=100a+4950d