Question

计算 求求大家帮帮忙

(+6\1)-(+3\1)-(-12\1) (13\6)+(-13\7)-(-2) 2\1+(-3\2)-(-5\4)+(-2\1)
-2.5+(-3又2\1)-(-2又3\1)+┃-3\2┃
(1-2\1)+(2\1-3\1)+(3\1-4\1)+.....+(2012\1-2013\1)

Answer 1

(+6/1)-(+3/1)-(-12/1)
=6/1+(-3/1)+12/1
=(6/1+12/1)+(-3/1)
=4/1+(-3/1)
=-(3/1-4/1)
=-12/1

(13/6)+(-13/7)-(-2)
=13/6+(-13/7)+2
=2-(13/7-13/6)
=2-13/1
=13/25

2/1+(-3/2)-(-5/4)+(-2/1)
=2/1+(-3/2)+5/4+(-2/1)
=[2/1+(-2/1)]+[(-3/2)+5/4]
=0+5/4-3/2
=15/2

-2.5+(-3又2/1)-(-2又3/1)+|-3/2|
=-2.5+(-3又2/1)+2又3/1+3/2
=[-2.5+(-3又2/1) ]+(2又3/1+3/2)
=-6+3
=-(6-3)
=-3

(1-2/1)+(2/1-3/1)+(3/1-4/1)+……+(2012/1-2013/1)
=1-2/1+2/1-3/1+3/1-4/1+……+2012/1-2013/1
=1-2013/1
=2013/2012