Question

计算下列各题（能简便计算的要简便计算）

21又7/8-(1.875+1又7/10) 7又3/7+（3又1/5-2又3/7)-2又1/5

2又2/3+0.8-（1.8-5/6） 1.625+4又6/7+(4又3/8-3又6/7）
再来一个方程。
x-（2又1/20+5.75）=8/15

Answer 1

1）原式=175/8 - (15/8 +17/10) + 16/5 -17/7 - 11/5
=175/8 - 15/8 -17/10 + 16/5 -17/7 - 11/5
=175/8 - 15/8 + 16/5 -11/5 -17/10 - 17/7
=20+1-17/10-17/7
=193/10-17/7
=1181/70
2）原式=8/3+0.8-1.8-5/6
=8/3-5/6-1
=6/16-5/6-1
=11/6-1
=5/6
3）原式=13/8+34/7+35/8-27/7
=13/8+35/8+34/7-27/7
=48/8+1
=56/8=7
4）化简后：x-41/20-115/20=8/15
x-156/20=8/15
x=156/20+8/15
x=39/5+8/15
x=117/15+8/15
x=25/3