[tex]\it \dfrac{^{3)}x-12}{\ 3}=\dfrac{4}{9} \Rightarrow \dfrac{3x-36}{9}=\dfrac{4}{9} \Rightarrow 3x-36=4|_{+36} \Rightarrow 3x=40|_{:3} \Rightarrow x=\dfrac{40}{3}\\ \\ \\ Sau:\\ \\ \dfrac{x-12}{\ 3}=\dfrac{4}{9} \Rightarrow x-12=\dfrac{\ 4\cdot3^{(3}}{9} \Rightarrow x-12=\dfrac{4}{3}|_{+12} \Rightarrow x=12+\dfrac{4}{3}=\\ \\ \\ =\dfrac{40}{3}[/tex]
