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(1+19/92)+(1+19/92x2)+(1+19/92x3)+.(1+19/92x90)+(1+19/92x91)的简便计算

题目详情
(1+19/92)+(1+19/92x2)+(1+19/92x3)+.(1+19/92x90)+(1+19/92x91)的简便计算
▼优质解答
答案和解析
(1+19/92)+(1+19/92x2)+(1+19/92x3)+.(1+19/92x90)+(1+19/92x91)
=1*91+19/92(1+2+3+4+……+90+91)
=91+19/92*(1+91)*91/2
=91+19*91/2
=91*(1+19/2)
=91*(10+1/2)
=910+45.5
=955.5