giải giúp tôi vs ạ , lm onnn

1) `[1/3(6/5-9/4)-7/5(15/14+5/7)]:(1/2-1/3+5/6)`

`=[1/3 . (-21/20)]-7/5 . 25/14:(1/6+5/6)`

`=-7/20-5/2:1`

`=-7/20-5/2`

`=-57/20`

2) `1/5:3/10+5/6(12/5-6/25+8/75)-18/17:9/34`

`=1/5 . 10/3+5/6(54/25+8/75)-18/17 . 34/9`

`=2/3+5/6 . 34/15-4`

`=2/3+17/9-4`

`=23/9-4`

`=-13/9`

3) `10/7:15/4-2/3(9/4-15/8):(1/5-3/10+9/20)`

`=10/7 . 4/15-2/3 . 3/8:(-1/10+9/20)`

`=8/21-1/4:7/20`

`=8/21-1/4 . 20/7`

`=8/21-5/7`

`=-1/3`

4) `-3/4:(1/4-5/8)+3/8(4/3-16/9)-5/7(14/15-21/10)`

`=-3/4:(-3/8)+3/8 . (-4/9)-5/7 . (-7/6)`

`=3/4 . 8/3-1/6+5/6`

`=2+2/3`

`=8/3`

5) `10/3:(-20/9)-8/7(21/4-14/8)-3/4(8/9)+12:24/7`

`=10/3 .(-9/20)-8/7 . 7/2-2/3+12. 7/24`

`=-3/2-4-2/3+7/2`

`=2-4-2/3`

`=-2-2/3`

`=-8/3`

6) `4/5(1/2-7/4)-3/4(1/3-8/12)+15/4:(-5/8)-6/5:1/10`

`=4/5 . (-5/4)-3/4 . (-1/3)+15/4 . (-8/5)-6/5 .10`

`=-1+1/4-6-12`

`=-19+1/4`

`=-75/4`

7) `-17/14:(-34/7)+10/3(1/5-3/4)-6/5(1/3-5/6)`

`=-17/14 .(-7/34)+10/3(-11/20)-6/5(-1/2)`

`=1/4-11/6+3/5`

`=-59/60`

8) `17/(-26)(1/6-5/3):17/13-20/3(2/5-1/4)+2/3(6/5-9/2)`

`=-17/26 . 13/17 .(-3/2) -20/3 . 3/20+2/3 . (-33/10)`

`=-1/2(-3/2)-1-11/5`

`=3/4-1-11/5`

`=-49/20`

9) `-8/9(9/8-3/2)+5/4:(5/2-15/4)-3/4(10/9-8/3):(-1/3)`

`=-8/9 .(-3/8)+5/4:(-5/4)-3/4(-14/9).(-3)`

`=1/3-1+7/6(-3)`

`=-2/3-7/2`

`=-25/6`

10) `21/10:(12/5-9/10)(-4/7)-3/2(1/6-7/12)+1/5(3/2-1/4)`

`=21/10 . (-4/7):3/2-3/2(-5/12)+1/5 . 5/4`

`=-6/5 . 2/3+5/8+1/4`

`=-4/5+5/8+1/4`

`=3/40`