简便运算:1⼀6+1⼀12+1⼀20+1⼀30+1⼀42+1⼀56+1⼀72+1⼀90

2024-12-18 02:43:45
推荐回答(2个)
回答1:

1/(2x3)+1/(3x4)+1/(4x5)+1/(5x6)+1/(6x7)+1/(7x8)+1/(8x9)+1/(9x10)
=1/2-1/3+1/3-1/4.......+1/9-1/10
=1/2-1/10=0.4

回答2:

1