If ∠1 is vertical to ∠2, then it means they are equal.
First you set the two equations equal to each other.
7x+1 = 5x+47
we have to get x on one side so we subtract one of the x...
7x+1 = 5x+47
-5x -5x then you get...
2x+1 = 47 now subtract 1
-1 -1
2x = 46, now divide both sides by 2, and you will get
x=23
( Please ask me if you have any more questions)