Question

急用啊！！！两道数学题！！！！

（1）1又1/2*5/7-（-5/7）*2又1/2+（-1/2）*5/7
（2）-3.14*65.2+6.28*（-23.3）-1.57*36.4
要详细过程啊！！！

Answer 1

1又1/2*5/7-(-5/7)*2又1/2+（-1/2）*5/7

=1又1/2*5/7+5/7*2又1/2-1/2*5/7

=(1又1/2+2又1/2-1/2)*5/7

=(1+1/2+2+1/2-1/2)*5/7

=(3+1/2)*5/7

=7/2*5/7

=5/2

=2+1/2

=2又1/2

-3.14*65.2+6.28*（-23.3）-1.57*36.4
=-3.14*65.2-2*3.14*23.3-0.5*3.14*36.4
=-3.14*65.2-46.6*3.14-18.2*3.14
=-3.14*(65.2+46.6+18.2)
=-3.14*130
=408.2

Answer 2

sha

Answer 3

（1）5/2

Answer 4

5/2
-2041/5