\(\dfrac{x+3}{15}=\dfrac{1}{3}\left(1\right)\\ \Leftrightarrow x+3=\dfrac{1}{3}\cdot15\\ \Leftrightarrow x+3=5\\ \Rightarrow x=5-3\\ \Rightarrow x=2\)
Vậy tập nghiệm phương trình (1) là \(\left\{2\right\}\)
(X+3)3=15x1
3X+9=15
3X=15-9
3X=6
X=6:3
X=2
\(\dfrac{x+3}{15}=\dfrac{1}{3}\)
\(\Rightarrow\dfrac{x}{15}+\dfrac{3}{15}=\dfrac{1}{3}\)
\(\Rightarrow\dfrac{x}{15}=\dfrac{1}{3}-\dfrac{3}{15}\)
\(\Rightarrow\dfrac{x}{15}=\dfrac{2}{15}\)
\(\Rightarrow x=2\)