4. Find the value of x.
(4x + 7)
(2x + 5)

Answer:
x = 28
Step-by-step explanation:
The 2 angles must add up to 180°, as definition of a line.
4x + 7 + 2x + 5 = 180
6x + 12 = 180
6x = 168
x = 28