Answer :
You would use substitution to set the equations equal and then manipulate the equation to get x alone
52x+15=46x+63
52x=46x+48
6x=48
X=8 hours
Then plug your x into one of your original formula's
Y=46x+63
Y=46(8)+63
Y=368+63
Y=431 miles
52x+15=46x+63
52x=46x+48
6x=48
X=8 hours
Then plug your x into one of your original formula's
Y=46x+63
Y=46(8)+63
Y=368+63
Y=431 miles