Answer:
x = 8
Step-by-step explanation:
There are two ways of answering this:
1.)Supplementary Angles/Linear pair:
(5x- 15) + (20x - 5) = 180°
25x - 20 = 180
25x - 20 +20 = 180 + 20
25x = 200
x = 8
2.) Vertical angles theorem:
(5x - 15) = (3x + 1)
5x - 3x -15 + 15 = 3x - 3x + 1 +15
2x = 16
x = 8
