These two angles add up to 180, so we can set up an equation. 5x-23+7x-1=180. Now we combine like variables, getting 12x-23-1=180. We add 23 to both sides, and get 12x-1=203. Then we add 1 to both sides, getting 12x=204. Finally we divide by 12 on both sides, with our result as x=17.
