well, keeping in mind that the sum of all exterior angles in a polygon always add up to 360°, and those angles in the picture are all exterior angles, so then
[tex]79~~ + ~~(x+10)~~ + ~~(2x)~~ + ~~(x-1)~~ = ~~360\implies 88+4x=360 \\\\\\ 4x=272\implies x=\cfrac{272}{4}\implies \boxed{x=68}[/tex]
