解:84右19分之4乘以1,375加1,375加105右19分之5乘以0.9=1600/19 * 1375/1000 + 1375/1000 +2000/19 * 9/10=2200/19 + 1375/1000 + 1800/19=4000/19 + 1375/1000 =211又17125/19000望采纳!