giúp em với em cảm ơn

`a)`

`2x-sqrt(1,69)=sqrt(1,21)`

`2x-1,3=1,1`

`2x=1,1+1,3`

`2x=2,4`

`x=(2,4)/2`

`x=1,2`

Vậy `x=1,2`

`b)`

`5*(sqrt(1/25)-x)-sqrt(1/81)=-1/9`

`5*(1/5-x)-1/9=-1/9`

`5*1/5-5x-1/9=-1/9`

`1-5x-1/9=-1/9`

`1-5x=0`

`-5x=-1`

`x=(-1)/(-5)`

`x=1/5`

Vậy `x=1/5`

`c)`

`2+1/6-x=10*sqrt(0,01)-sqrt(25/36)`

`2+1/6-x=1-5/6`

`13/6-x=1/6`

`13/6-1/6=x`

`x=(13-1)/6`

`x=12/6`

`x=2`

Vậy `x=2`

`d)`

`|x-0,02|+1,5=2 1/2`

`|x-0,02|+1,5=2,5`

`|x-0,02|=2,5-1,5`

`|x-0,02|=1`

`x-0,02=1` hoặc `x-0,02=-1`

`x=1+0,02` hoặc `x=-1+0,02`

`x=1,02` hoặc `x=-0,98`

Vậy `x\in{-0,98;1,02}`