Question

6道计算题（能简便的就简便

1
（20.1-21×7分之6）÷5.1
2
0.2+【6分之5×（0.15+20分之9）】
3
3.64×【1÷（20分之21-2.09）】
4
8.5×4分之3+0.75×5+6.5÷1又3分之1
5
【15分之8-（12分之7-5分之2）】×14分之15
6
11分之5×【（5分之4+3分之1）÷6分之5】
快点，做得好的我再加分！

Answer 1

（20.1-21×7分之6）÷5.1
=(20.1-18)÷5.1
=2.1÷5.1
=21/10÷51/10
=21/10 × 10/51
=21/51
=7/17

0.2+[6分之5×（0.15+20分之9）]
=0.2+[5/6 ×(3/20+9/20)]
=0.2+(5/6 × 6/10)
=0.2+0.5
=0.7

3.64×[1÷（20分之21-2.09）]
=3.64 × [1÷（1又5/100-2又9/100)]
=3.64×[1÷（-1又4/100)]
=-3.64×(1×100/104)
=-364/100×100/104
=-364/104
=-7/2

8.5×4分之3+0.75×5+6.5÷1又3分之1
=8.5×3/4+3/4×5+6.5×3/4
=3/4×(8.5+5+6.5)
=3/4×20
=15

[15分之8-（12分之7-5分之2）]×14分之15
=(8/15-7/12+2/5)×15/14
=8/15×15/14-7/12×15/14+2/5×15/14
=8/14-5/8+6/14
=1-5/8
=3/8

11分之5×[（5分之4+3分之1）÷6分之5]
=5/11×(4/5+1/3)×6/5
=5/11×6/5×(4/5+1/3)
=6/11×17/15
=34/55

Answer 2

（20.1-21×6/7）÷5.1 0.2+【5/6×（0.15+9/20）】 3.64×【1÷（21/20-2.09）】
=(20.1-18)×10/51 =0.2+[5/6×6/10] =3.64×[1÷(减不了)
=21/10×10/51 =0.2+0.5
=7/17 =0.7

8.5×3/4+0.75×5+6.5÷1又1/3 【8/15-（7/12-2/5）】×15/14
=13.5×0.75+6.5×3/4 =【8/15+2/5-7/12）】× 15/14
= 20 ×3/4 =4/7+3/7-5/8
=15 =3/8

5/11×【（4/5+1/3）÷5/6】
=5/11 ×17/15×6/5
=1/11×17/5×2
=34/55
不知对否。