已知1⼀2*1⼀3=1⼀2-1⼀3,1⼀4*1⼀5=1⼀4-1⼀5,计算1⼀2*1⼀3+1⼀3*1⼀4+1⼀4*1⼀5+1⼀5*1⼀6+......+1⼀9*1⼀10

2024-12-16 13:47:55
推荐回答(2个)
回答1:

1/2*1/3+1/3*1/4+1/4*1/5+1/5*1/6+......+1/9*1/10
=1/2-1/3+1/3-1/4……+1/9-1/10
=1/2-1/10
=5/10-1/10
=2/5

回答2:

1/2*1/3+1/3*1/4+1/4*1/5+1/5*1/6+......+1/9*1/10
=½-1/3+1/3-¼+¼-1/5+···+1/9-1/10
=½-1/10
=4/10
=2/5