Answer:
x = 20
Step-by-step explanation:
The two angles inside the triangle added together equals the one other angle that's outside the triangle. Its called an exterior angle.
42° + 5x + 4 = 7x + 6
combine like terms
5x + 46 = 7x + 6
subtract 5x
46 = 2x + 6
subtract 6
40 = 2x
divide by 2
20 = x
