(1/2 -1/6 ) . 3^x+4 - 4 . 3^x = 3^17 -4 . 3^13

`#Yaii `
`(1/2-1/6).3^(x+4)-4.3^x=3^17-4.3^13 `

`<=>1/3  .3^x  .3^4-4.3^x=3^13  .3^4-4.3^13 `

`<=>3^x.(1/3  .3^4-4)=3^13  .(3^4-4) `

`<=>3^x.(1/3  .81-4)=3^13  .(81-4) `

`<=>3^x.(27-4)=3^13  .77 `

`<=>3^x  .23=3^13  .77 `

`<=>3^x=3^13  .77:23 `

`<=>3^x=3^13  .  77/23 `

`<=>3^x=1594323  .  77/23 `

`<=>3^x=5337516,13(vô  lí) `

`<=>x∈∅ `

`=> ` Vậy `x∈∅ `