出20道带加.减.乘.除的负数或分数算试(要过程和答案

1. 3/7 × 49/9 - 4/3 =7/3-4/3=1
2. 8/9×15/36+1/27 =8/9×5/12+1/27=10/27+1/27=11/27
3. 12× 5/6 – 2/9 ×3=10-2/3=28/3
4. 8× 5/4 + 1/4 =10+1/4=41/4
5. 6÷ 3/8 – 3/8 ÷6 =16-1/16=255/16
6. 4/7 × 5/9 + 3/7 × 5/9=(4/7+3/7)×5/9=5/9
7. 5/2 -（ 3/2 + 4/5 ）=5/2-3/2-4/5=1/5
8. 7/8 + （ 1/8 + 1/9 ）=7/8+1/8+1/9=10/9
9. 9 × 5/6 + 5/6 =5/6×(9+1)=25/3
10. 3/4 × 8/9 - 1/3 =2/3-1/3=1/3
11. 50＋160÷(-40)=50-160÷40=50-4=46
12.120-144÷18+(-35)=120-8-35=77
13.347+45×2-(-4160)÷(-52)=347+90-80=357
14（58+37）÷[64-(-9)×(-5)]=95÷[64-45]=95÷19=5
15.(-95)÷（64-45）=-95÷19=-5
16.178-145÷(-5)×6+42=220+145÷5×6=220+174=394
17.812-700÷[-（9+31×11）]=812+700÷(9+341)=812+700÷350=814
18.85+(-14)×（14+208÷26）=85-14×(14+8)=85-14×22=85-308=-223
19.（284+16）×[-(512-8208÷18）]=-300×[512-456]=-300×56=-16800
20.120-36×(-4)÷18+35 =120+2×4+35=163