Respuesta :

5y and 3x-y are vertical angles i.e. they are equal
5y=3x-y
6y=3x

5y+2x+y=180, because it is a straight line
6y+2x=180, then sub 6y for 3x
3x+2x=180
5x=180
5x/5=180/5
x=36

Answer: 36