Five years ago ,a father was four times as old as his son. In five years time the father will be twice as old as the son. If x and y are the present ages of the father and the son respectively, the equation relating x and y are: Please I need an explanation
The options are
A: 4y-x=0;x-2y=0
B: 4y-x=15;x-2y=5
C: 4y-x=25;x-2y=5
D: x-4y=15;y-2x=5