1.如果a=-1/4,b=-2,c=-2 3/4,那么|a|+|b|-|c|=()

问题描述:

1.如果a=-1/4,b=-2,c=-2 3/4,那么|a|+|b|-|c|=()
2.+0.125+(+3 1/4)+(-3 1/8)-1/8-(-1/4)
3.3.75-[(-3/8)+(-1/2)-(-5/6)+4 2/3]-0.125
4.(-1 1/2)-1 1/4+(-2 1/2)-(-3 3/4)-(-1 1/4)
5.1-5/12+4/15+1/12-14/15-1 19/20

1,|a|+|b|-|c|=1/4+2-2-3/4=-1/2
2,=1/8+3+1/4-3-1/8-1/8+1/4=3/8
3,=3+3/4+3/8+1/2-5/6-4-2/3-1/8=3+8/8+1/2-5/6-2/3-4=3/6-5/6-4/6=-1
4,=-1-1/2-1-1/4-2-1/2+3+3/4+1+1/4=-2-2/4-2-2/4+3+3/4+1=-4/4+3/4=-1/4
5,=1-4/12+4/15-14/15-1-19/20=1-1/3-2/3-1-19/20=39/20 或=1又20分之19