Explanation
By definition, both angles are supplementary; namely, they add up to 180°. This fact gives us the equation
[tex](2x+6)+(x+3)=180\degree[/tex]
Let's solve it for x:
[tex]\begin{gathered} (2x+x)+(6+3)=180\degree,\text{ rearrangement of the terms on the left} \\ 3x+9=180\degree, \\ 3x=171\degree, \\ x=\frac{171\degree}{3}, \\ x=57\degree\text{.} \end{gathered}[/tex]Answer
The value of x is
[tex]x=57\degree\text{.}[/tex]
The values of the angles are
