Step 1
Find the value of x using the law that the sum of angles on a straight line is 180°
[tex]\begin{gathered} x^o+110^o=180^o \\ x^o=(180-110)^o \\ x^0=70^o \end{gathered}[/tex]Step 2
Find the value of (x -50)° by substitution
[tex](70-50)^{o^{}}=20^o[/tex]