x=-2.8 y=-5.2

问题描述:

x=-2.8 y=-5.2
1.x-y 2.-x-y 3.-x+y 4 /x/-/y/

1.x-y
=-2.8-(5.2)
=-2.8+5.2
=2.4
2.-x-y
=2.8+5.2
=8
3.-x+y
=2.8+(-5.2)
=2.8-5.2
=-2.4
4 /x/-/y/
=2.8-5.2
=-2.4