These angles are adjacent angels.
adjacent angels- have a common side and the same vertex.
(pictured below)
To solve this we set the sum of both angles equal to 180°. We do this because they are two adjacent angles on a straight line. The measure of a straight lines angle is 180°.
180= 5x + (x+96)
180=6x+96
84= 6x
x=14
any questions?