1-6/5+12/7-20/9+30/11-42/13+56/15-72/17+90/19简算
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/27 16:42:18
![1-6/5+12/7-20/9+30/11-42/13+56/15-72/17+90/19简算](/uploads/image/z/33716-20-6.jpg?t=1-6%2F5%2B12%2F7-20%2F9%2B30%2F11-42%2F13%2B56%2F15-72%2F17%2B90%2F19%E7%AE%80%E7%AE%97)
1-6/5+12/7-20/9+30/11-42/13+56/15-72/17+90/19简算
1-6/5+12/7-20/9+30/11-42/13+56/15-72/17+90/19简算
1-6/5+12/7-20/9+30/11-42/13+56/15-72/17+90/19简算
1-5/6+7/12-9/20+11/30-13/42+15/56-17/72+19/90 =1-(1/2+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)+(1/9+1/10) =1-1/2+1/10 =3/5