51问答网 > 1+1⼀3-7⼀12+9⼀20-11⼀30+13⼀42-15⼀56+17⼀72=?

1+1⼀3-7⼀12+9⼀20-11⼀30+13⼀42-15⼀56+17⼀72=?

2024-12-22 00:36:09

推荐回答（2个）

回答1：

1+1/3-7/12+9/20-11/30+13/42-15/56+17/72
=1+1/3-(3+4)/12+(4+5)/20-(5+6)/30+(6+7)/42-(7+8)/56+(8+9)/72
=1+1/3-1/3-1/4+1/4+1/5-1/5-1/6+1/6+1/7-1/7-1/8+1/8+1/9
=1+1/9
=10/9

回答2：

1+1/3-7/12+9/20-11/30+13/42-15/56+17/72
=1+1/3-1/3-1/4+1/4+1/5-1/5-1/6+1/6+1/7-1/7-1/8+1/8+1/9
=1+1/9
=1又1/9