2/5+1/4+3/8 11/9-2/7-5/7 11/25+(1/12+14/25) 15/18-(15/18-11/12) 简算,急
问题描述:
2/5+1/4+3/8 11/9-2/7-5/7 11/25+(1/12+14/25) 15/18-(15/18-11/12) 简算,急
2/5+1/4+3/8
11/9-2/7-5/7
11/25+(1/12+14/25)
15/18-(15/18-11/12)
答
2/5+1/4+3/8 =2/5+(2/8+3/8)=2/5+5/8=16/40+25/40=41/4011/9-2/7-5/7 =11/9-(2/7+5/7)=11/9-1=2/911/25+(1/12+14/25)=(11/25+14/25)+1/12=1+1/12=13/1215/18-(15/18-11/12)=15/18-15/18+11/12=11/12