Hello! Please help me solve this Geometry question. Anything helps!

Answer:
[tex]x = 51[/tex]
Step-by-step explanation:
[tex]the \: sum \: of \: the \: exterio \: angles\: a \\ \: polygon \: is \: 360. \\ \\ 64 + 60 + 69 + 42 + x + (x + 23) = 360 \\ 335 + 2x + 23 = 360 \\ x = \frac{360 - 258}{2} = 51[/tex]