Đáp án`+`Giải thích các bước giải:

 Cau `1:`

`a) 3/5 + 2/5 . (-15/4)`

`= 3/5 -3/2`

`=-9/10`

`b) |-5|-(-3/11)^0 +(1/2)^5 .64`

`= 5-1+1/32 . 64`

`=4+2`

`=6`

`c) -7/11 . 31/37 +(-7)/11 . 6/37 + 3 7/7`

`= -7/11 . (31/37 + 6/37)+ 4`

`= -7/11. 1 +4`

`=-7/11 +4`

`=37/11`

`d) 6,76 - 23/17 -(-2,24)-(-6/17)`

`= 169/25 - 23/17 56/25 + 6/17`

`=(169/25 +56/25)+(-23/17+6/17)`

`=9 -1`

`=8`

Cau `2:`

`a) 0,5-x=-7/5`

`x=0,5+7/5`

`x=19/10`

Vậy `x=19/10`

`b) -1/3x+5/6=1,2`

`-1/3x=1,2 -5/6`

`-1/3x=11/30`

`x=11/10 :(-1/3)`

`x=-11/10`

Vậy `x=-11/10`

`c) sqrt(9/16) +1/2:x=-1/4`

`3/4 +1/2:x=-1/4`

`1/2:x=-1/4-3/4`

`1/2:x=-1`

`x=1/2:(-1)`

`x=-1/2`

Vậy `x=-1/2`

Vậy `x=-1/3`

`d) |3x-5|-2/3=|-1/3|`

`|3x-5|-2/3=1/3`

`|3x-5|=1/3 +2/3`

`|3x-5|=1`

`3x-5=1` hoặc `3x-5=-1`

`3x=6` hoặc `3x=4`

`x=2` hoặc `x=4/3`

Vậy `x∈{2;4/3}`