简便 49.5/9+35.1/7.8 {2.5-8分之31/(6分之11+0.75)}*17分之30 19.63*99+19.63 (7.6-105*0.6)*13分10

问题描述:

简便 49.5/9+35.1/7.8 {2.5-8分之31/(6分之11+0.75)}*17分之30 19.63*99+19.63 (7.6-105*0.6)*13分10

49.5/9+35.1/7.8 =5.5+4.5=10{2.5-8分之31/(6分之11+0.75)}*17分之30 ={2.5-31/8÷31/12}×30/17={2.5-1.5}×30/17=30/1719.63*99+19.63=19.63×(99+1)=19.63×100=1963(76-105*0.6)*13分10 =(76-63)×10/13...