## Geometry: Common Core (15th Edition)

The two angles are a linear pair, so are supplementary. $(3x+31)+(2x-6)=180$ combine like terms $5x+25=180$ subtract 25 from each side $5x+25-25=180-25$ simplify $5x=155$ divide each side by 5 $5x\div5=155\div5$ $x=31$