简便计算 23X(-5)-(-3)/   3/128          2.-7x(-3)x(-0.5)+(-12)x(

23X(-5)-(-3) ÷ 3/128
=-115+128
=13
2.-7x(-3)x(-0.5)+(-12)x(-2.6)
=21×（-0.5）+31.2
=-10.5+31.2
=20.7
3.(1 又3/4-7/8-7/12)/(-7/8)+(-7/8)/(1 又3/4-7/8-7/12)
=7/24÷（-7/8）-7/8÷7/24
=-1/3-3
=-3又1/3
4.-|-2/3|—|-1/2*2/3|—|1/3—1/4|—|-3|
=-2/3-1/3-1/3+1/4-3
=-4/3+1/3-3
=-4又1/12