0.75*15+4.5*2.5 3.6*31.4+43.9*6.4 简便计算

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/12 01:30:45
0.75*15+4.5*2.5 3.6*31.4+43.9*6.4 简便计算

0.75*15+4.5*2.5 3.6*31.4+43.9*6.4 简便计算
0.75*15+4.5*2.5 3.6*31.4+43.9*6.4 简便计算

0.75*15+4.5*2.5 3.6*31.4+43.9*6.4 简便计算
0.75*15+4.5*2.5
=45/4+45/4=45/2=22.5
3.6*31.4+43.9*6.4
=(1-6.4)*31.4+43.9*6.4
=31.4-6.4*(43.9-31.4)
=31.4-32/5*5/2
=31.4-16
=15.4

0.75*15+4.5*2.5
=(1-0.25)*15+4.5*2.5
=15-2.5*1.5+4.5*2.5
=15+2.5*(4.5-1.5)
=15+7.5
=22.5
3.6*31.4+43.9*6.4
=(10-6.4)*31.4+43.9*6.4
=314+6.4*(43.9-31.4)
=314+6.4*12.5
=314+80
=394

=0.75*15+0.25*10*4.5
=0.75*15+0.25*15*3
=15*(0.75+0.75*3)
=15*3
=45