有理数加减法运算(+2/7)+(-5/2)+(-12/7)+(+2.5)+(-0.125)+(-19/8)怎么解

问题描述:

有理数加减法运算(+2/7)+(-5/2)+(-12/7)+(+2.5)+(-0.125)+(-19/8)怎么解

(+2/7)+(-5/2)+(-12/7)+(+2.5)+(-0.125)+(-19/8)
=2/7-5/2-12/7+2.5-0.125-19/8
=(2/7-12/7)-2.5+2.5-0.125-2.375
=-10/7-5/2
=-(20+35)/14
=-55/14