Câu 2 (1,5 điểm) Tìm x: a) $\frac{3}{4}$x + $\frac{5}{2}$ = $\frac{23}{8}$ b) |2x - $\frac{1}{3}$| + $\frac{3}{2}$ = 2 c) ($3^{x}$ - 27)(2$\sqrt[]{x}$ - 4) = 0

`Accnswer`

 `a)3/4 x+5/2=23/8`

`=>3/4x=3/8`

`=>x=3/8:3/4`

`=>x=3/8 . 4/3`

`=>x=1/2`

Vậy `x=1/2`

`b)|2x-1/3|+3/2=2`

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

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

`@` Trường hợp `1:`

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

`=>2x=1/2+1/3`

`=>2x=5/6`

`=>x=5/6:2`

`=>x=5/6 . 1/2`

`=>x=5/12`

`@` Trường hợp `2:`

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

`=>2x=-1/2+1/3`

`=>2x=-1/6`

`=>x=-1/6:2`

`=>x=-1/6 . 1/2`

`=>x=-1/12`

Vậy `x in {5/12;-1/12}`

`c)(3^x -27)(2sqrt{x}-4)=0(Đk: x>=0)`

`@` Trường hợp `1:`

`3^x-27=0`

`=>3^x=27`

`=>3^x=3^3`

`=>x=3(TMĐK)`

`@` Trường hợp `2:`

`2sqrt{x}-4=0`

`=>2sqrt{x}=4`

`=>sqrt{x}=2`

`=>x=2^2`

`=>x=4(TMĐK)`

Vậy `x in{3;4}`