2、 1/2-2/3+4/5- 1/2- 1/3=4/5- 1=- 1/5

3、=-3/2+ 17/4+ 1 1/4- 1 1/2=28/4-7=0

4、=40-63=-23

5,4-5 * (1/2) 3 = 4+5/8 = 4 and 5/8.

6、=-2/5-5/6+49/ 10-6/ 10=46/ 15

7、 100/5*(-2/5)=20*(-2/5)=-8

8,5 * (6)-(-4)/(-8) =-30-1/2 =-30 and1/2.

9,2 and1/4 * (6/7) * (1/2-2) = 9/4 * (6/7) * (-3/2) = 81/28.

1 1, (-16*50 divided by 3 2/5)+(-2) = (-272/17-250/17)+(-2) =-

12、(-6)*8-(-2)^2-(-4)^2*5=-48-4- 16*5=- 132

13、(- 1/2)^2+ 1/2*(2/3-/2/3-2/)= 1/4+(- 1/3)=- 1/ 12

14、=- 1- 1/2* 1/3=-7/6

Yes, some questions are unclear. The original questions should be treated differently. Use it if it works, what's the big deal!