1-1/2+5/6-7/12+9/20-30/11
问题描述:
1-1/2+5/6-7/12+9/20-30/11
答
1-1/2+5/6-7/12+9/20-11/30
= 1-1/2+(2+3)/(2x3) - (3+4)/(3x4)+ (4+5)/(4x5)-(5+6)/(5x6)
= 1 - 1/2 + 1/2 + 1/3 - 1/3 - 1/4 + 1/4 +1/5 -1/5 - 1/6
= 1 - 1/6
= 5/6