Explanation:
(5x-20) and (3x+8) will be equal since they are Vertically Opposite Angles
5x - 20 = 3x + 8
5x - 3x = 8 + 20
2x = 28
x = 28/2 = 14
now, (5x - 20) and (5x+ 4y) will sum up to 180 degrees because they form a linear pair.
so,
5x - 20 + 5x + 4y = 180 degrees
(5*14) - 20 + (5*14) + 4y = 180
70 - 20 + 70 + 4y = 180
140 - 20 + 4y = 180
120 + 4y = 180
4y = 180 - 120
4y = 60
y = 60/4
y = 15
the value of x=14 and value of y=15