Question

能简便的就简便计算

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

1、原式=2.1÷5.1=7/17
2、原式=0.2+[5×(3/20+9/20)/6]=0.2+1/2=0.7
3、原式=(91/25)×[1÷(1/20-109/100)]=91/25×(-25/26)=7/2
4、原式=(3/4)×(8.5+5+6.5)=15
5、原式=(8/15)×(15/14)-(7/12)×(15/14)+(2/5)×(15/14)=4/7-5/8+3/7=1-5/8=3/8
6、原式=(5/11)×(6/5)×(4/5+1/3)=(6/11)×(17/15)=34/55

Answer 3

【2】0.2+[5/6×(0.15+9/20)]
=1/5+5/6×(3/20+9/20)
=1/5+5/6×4/5
=1/5+2/3
=13/15

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

【5】
[8/15-(7/12-2/5)]×15/14
=8/15×15/14-11/60×15/14
=4/7-11/(7*8)
=(32-11)/56
=3/8

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

其它不能简便

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不能简便的就直接计算