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𝓟𝓪𝓻𝓴𝓬𝓱𝓪𝓮𝔂𝓸𝓾𝓷𝓰

`a,`

`390-(x-20)=169:13`

`=> 390-x+20=13`

`=> 410-x=13`

`=> x=410-13`

`=> x=397`

Vậy `x=397`

`b,`

`(x-140):5=3^3-2^3 . 3`

`=> (x-140):5=27-24`

`=> (x-140):5=3`

`=> x-140=15`

`=> x=15+140`

`=> x=155`

Vậy `x=155

`c,`

`[(5x+2):7-6].17=340`

`=> (5x+2):7-6=20`

`=> (5x+2):7=26`

`=> 5x+2=182`

`=> 5x=180`

`=> x=36`

Vậy `x=36`

`d,`

`5+3^x=2(4^2-3^2)`

`=> 5+3^x=2.7`

`=> 5+3^x=14`

`=> 3^x=14-5`

`=> 3^x=9`

`=> 3^x=3^2`

`=> x=2`

Vậy `x=2`

`e,`

`(x+4)^2-7^10:7^8=0`

`=> (x+4)^2-7^2=0`

`=> (x+4)^2=7^2`

`TH1:`

`x+4=7`

`=> x=7-4`

`=> x=3`

`TH2:`

`x+4=-7`

`=> x=-7-4`

`=> x=-11`

Vậy `x=3` hoặc `x=-11`