## Elementary Geometry for College Students (7th Edition) Clone

Using the known supplementary angles, we obtain: $2x - y + 150 = 180 \\ 2x -y = 30$ And: $2x + y + 130 = 180 \\ 2x + y = 50$ Substituting $y = 50 -2x$ into the first equation, we find: $2x - 50 + 2x = 30 \\ 4x = 80 \\ x = 20$ Thus: $y = 50 - 2(20) = 10$