简便计算 80又1/7*7/8+71又1/6*6/7+61又1/5*5/6+51又1/4*4/5+41又1/3*3/4

简便计算 80又1/7*7/8+71又1/6*6/7+61又1/5*5/6+51又1/4*4/5+41又1/3*3/4
简便计算 80又1/7*7/8+71又1/6*6/7+61又1/5*5/6+51又1/4*4/5+41又1/3*3/4

简便计算 80又1/7*7/8+71又1/6*6/7+61又1/5*5/6+51又1/4*4/5+41又1/3*3/4
80又(1/7)*(7/8)+71又(1/6)*(6/7)+61又(1/5)*(5/6)+51又(1/4)*(4/5)+41又(1/3)*(3/4)
=(561/7)*(7/8)+(427/6)*(6/7)+(306/5) *(5/6)+(205/4)*(4/5)+(124/3)*(3/4)
=561/8+427/7+306/6+205/5+124/4
=561/8+248/8+61+51+41
=809/8+153
=101又(1/8)+153
=254又(1/8)