x+ y = 90
x = 36 + 3y
x = 36 + 3(90 - x)
x = 36 + 270 - 3x
4x = 306
x = 153/2 = 76.5 degrees
Answer: 76.5 degrees
Check: y=90=76.5 = 13.5 degrees
3y+36 =3(13.5)+36 = 76.5 good
7.3m questions
9.7m answers