Answer:
52
Step-by-step explanation:
Vertical angles are equal
<a = <B
5x -28 = 3x+4
Subtract 3x from each side
5x-3x-28 = 3x+4-3x
2x-28 = 4
Add 28 to each side
2x-28+28 = 4+28
2x= 32
Divide by 2
2x/2 = 32/2
x = 16
<A = <B = 3x+4 = 3(16)+4 = 48+4 = 52