42+1/3+1/9+1/27+1/81+1/243+1/729
问题描述:
42+1/3+1/9+1/27+1/81+1/243+1/729
答
原式=41+(1+1/3+1/9+1/27+1/81+1/243+1/729)
=41+【1-(1/3)六次方】/(1-1/3)=41+(728/729)/(2/3)=41+364/243=42+121/243
一楼算错了