Since they are vertical angles.... you have to set them equal to each other so
7x-7= 4x+14
Then you gotta solve it from there.
Subtract 4x to both sides
3x-7=14
Add 7 to both sides
3x=21
divide 3 to both sides
x=3
Hope that this helped you out hon :) BTW YOU ARE SO PRETTY OM FG