Question

1 and 2 are a linear pair, and 2 and 3 are vertical angles. m 2=(5+4 y) and m 3=(6 y-25). what is m 1

Answer 1

vertical angles are equal to each other:
∠2 = ∠3
5 + 4y = 6y - 25
→ 30 = 2y
→ 15 = y

∠2 = 5 + 4y = 5 + 4(15) = 5 + 60 = 65

linear pairs equal 180:
∠1 + ∠2 = 180
→ ∠1 + 65 = 180
→ ∠1 = 115