Answer:
39°
Step-by-step explanation:
If it gives you 2 angles and asks for x, you know it has 3 angles. So the shape is a triangle. All 3 angles in a triangle add up to 180°.
So add 78 and 63 which equals 141
[tex]78+63=141[/tex]
And to find x, subtract 141 from 180 because 180 is the total.
[tex]180-141=39[/tex]
So the answer is 39
