Răspuns
Explicație pas cu pas:
[tex]\dfrac{3^{2020}-3^{2019}-3^{2018}}{5}=\dfrac{9^{1009}}{x}\\\\\dfrac{3^{2018}(3^2-3-1)}{5}=\dfrac{(3^2)^{1009}}{x}\\\\\dfrac{3^{2018}(9-3-1)}{5} = \dfrac{3^{2018}}{x}\\\\\dfrac{3^{2018}\cdot 5}{5}=\dfrac{3^{2018}}{x}\\x\cdot 3^{2018}=3^{2018}\\\boxed{\bold{x=1}}[/tex]
