By adding B=6i-8i the restaurant then becomes (x+6)i + (y-8)j
The restaurant is in positive x direction which gives y=8
The magnitude of A and the restaurant are the same
x^2+y^2=(x+6)^2
12x=y^2-36=(8)^2-36=28
This gives x=7/3
Therefore vector A=(7/3) i +8j
The magnitude of A=sqrt [(7/3)^2+(8)^2]=25/3
A makes with positive x direction angle tan^(-1)
[8/(7/3)]
= tan^(-1) (24/7)
Hope this helps! :3