计算:(1+5/66(六十六分之五)*1)+(1+5/66*20)+(1+5/66*3)+……+(1+5/66*11)急!
问题描述:
计算:(1+5/66(六十六分之五)*1)+(1+5/66*20)+(1+5/66*3)+……+(1+5/66*11)急!
答
(1+5/66x1)+(1+5/66x2)+(1+5/66*3)+……+(1+5/66*11)
=1+1+..+1+5/66x1+5/66x2...+5/66x11
=11+5/66x(1+2+..+11)
=11+5/66x(1+11)x11÷2
=11+5/66x66
=11+5
=16