1、3.6/4-1.2x52、90/(3.6-1.8)3、(31.6-11.7)/2.5/0.44、3.4x7.8/3.

1、
3.6/4-1.2x5
=0.9-6
=-5.1
2、
90/(3.6-1.8)
=90÷1.8
=50
3、
(31.6-11.7)/2.5/0.4
=19.9÷（2.5×0.4）
=19.9
4、
3.4x7.8/3.9
=3.4×2
=6.8
5、
5.23x4+4.77/0.25
=5.23×4+4.77×4
=（5.23+4.77）×4
=40

1. 0.9-6=5.1

2. 90/1.8=900/18=50

3. (31.6-11.7)/2.5/0.4=19.9/(2.5*0.4)=19.9

4. 3.4x7.8/3.9=3.4*2=6.8

5. 5.23x4+4.77/0.25=4(5.23+4.77)=40

1. 0.9-6=5.1

2. 90/1.8=900/18=50

3. (31.6-11.7)/2.5/0.4=19.9/(2.5*0.4)=19.9

4. 3.4x7.8/3.9=3.4*2=6.8

5. 5.23x4+4.77/0.25=4(5.23+4.77)=40

相信你，加油