giúp mik bài này vs ak mik cảm ơn

hứa cho 5 sao và 30 điểm

Đáp án `+` Giải thích các bước giải:

 `2`

`a)3/4+1/4:x=-1/3`

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

`1/4:x=-13/12`

`x=1/4:(-13/12)`

`x=1/4.(-12/13)`

`x=-3/13`

Vậy `x=-3/13`

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`b)1/3.(2/5x-8/15)-3/4=0`

`1/3.(2/5x-8/15)=0+3/4`

`1/3.(2/5x-8/15)=3/4`

`2/5x-8/15=3/4:1/3`

`2/5x-8/15=9/4`

`2/5x=9/4+8/15`

`2/5x=167/60`

`x=167/60:2/5`

`x=167/24`

Vậy `x=167/24`

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`c)(2^x -4).(3.\sqrt{x}-9)=0`

`*TH1:2^x -4=0`

`2^x=4`

`2^x=2^2`

`x=2`

`*TH2:3\sqrt{x}-9=0`

`3\sqrt{x}=9`

`\sqrt{x}=3`

`x=3^2`

`x=9`

Vậy `x\in{2;9}`

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`d)4-(2x-1)^3=5/8`

`(2x-1)^3=4-5/8`

`(2x-1)^3=27/8`

`(2x-1)^3=(3/2)^3`

`2x-1=3/2`

`2x=3/2+1`

`2x=5/2`

`x=5/2:2`

`x=5/4`

Vậy `x=5/4`

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`e)|2x+1/3|-0,1=50%`

`|2x+1/3|-1/10=1/2`

`|2x+1/3|=1/2+1/10`

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

`*TH1:2x+1/3=3/5`

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

`2x=4/15`

`x=4/15:2`

`x=2/15`

`*TH2:2x+1/3=-3/5`

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

`2x=-14/15`

`x=-14/15:2`

`x=-7/15`

Vậy `x\in{2/15;-7/15}`

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`f)2/3 .3^{x+1} - 7.3^x=-405`

`2/3 .3^x.3-7.3^x=-405`

`3^x  .2-7.3^x = -405`

`3^x .(2-7)=-405`

`3^x .(-5)=-405`

`3^x =-405:(-5)`

`3^x=81`

`3^x=3^4`

`x=4`

Vậy `x=4`