$\begin{array}{c} \color{#db8}{\texttt{Cre: Capybara}} \end{array}$
`(5x-3)^3 + 11 = 354`
`=> (5x-3)^3 = 354 - 11`
`=> (5x-3)^3 = 343`
`=> (5x-3)^3 = 7^3`
`=> 5x-3=7`
`=> 5x=7+3`
`=> 5x = 10`
`=> x=10:5`
`=> x=2`
Vậy: `x=2`
`(5x - 3)^3 + 11 = 354`
`=> (5x -3)^3 = 354 - 11`
`=> (5x - 3)^3 = 343`
`=> (5x - 3)^3 = 7^3`
`=> 5x - 3 = 7`
`=> 5x = 7 + 3`
`=> 5x = 10`
`=> x = 10 : 5`
`=> x = 2`
Vậy...