14.75x6.88-87.5x0.688+14.75x3.12-0.0875x312=14.75x6.88+14.75x3.12-8.75x6.88-8.75x3.12=14.75x(6.88+3.12)-8.75x(6.88+3.12)=14.75x10-8.75x10=147.5-87.5=604.7x0.35+0.47x4.2+0.047x23的简便运算采纳了再提问