Answer:
see explanation
Step-by-step explanation:
∠ YXW = ∠ ZXV ( vertically opposite angles ) , so
4a + 15 = 2a + 65 ( subtract 2a from both sides )
2a + 15 = 65 ( subtract 15 from both sides )
2a = 50 ( divide both sides by 2 )
a = 25
Then
(7)
∠ ZXV = 2a + 65 = 2(25) + 65 = 50 + 65 = 115°
(8)
∠ YXW = ∠ ZXV = 115°
∠ ZXY and ∠ ZXV are adjacent angles and sum to 180° , that is
(9)
∠ ZXY = 180° - 115° = 65°
(10)
∠ VXW = ∠ ZXY = 65° ( vertically opposite angles
