简单,
(-8)-(-15)+(-9)-(-12)
=(-8)+15-9+12
=10
3/5-3/2+(-11/4)+13/4
=3/5-3/2-11/4+13/4
=-11/20
31+(-5/4)+0.25
=31-5/4+0.25
=30
49-(-20.6)-3/5
=49+20.6-3/5
=69
7-(1/2)+1.5
=7-0.5+1.5
8
不会的问我,踩我,一定要踩我
简单,
(-8)-(-15)+(-9)-(-12)
=(-8)+15-9+12
=10
3/5-3/2+(-11/4)+13/4
=3/5-3/2-11/4+13/4
=-11/20
31+(-5/4)+0.25
=31-5/4+0.25
=30
49-(-20.6)-3/5
=49+20.6-3/5
=69
7-(1/2)+1.5
=7-0.5+1.5
8
不会的问我,踩我,一定要踩我