I have a system of equations that illustrates two different floor plans (60 total) for sale, four times more of the second are available than the first (x= the first floor plan, y=the second:

x+y=60

y=x(4)

I need help solving how many of each are available via substitution. I assumed that I could substitute y for x (y+1)in the first equation but that is not checking. I appreciate help with this!