The sum of the interior angles of a triangle is 180. Besides, the angle that is missing is suplementary (sums 180) to 153. So we have the next equation
[tex]\begin{gathered} (x-4)+(2x+10)+(180-153)=180 \\ x+2x=180+4-10-180+153 \\ 3x=147 \\ x=49 \end{gathered}[/tex]
