Let the numbers be n and m, with n > m
n + m = 5(n - m)
Distribute the 5 on the right
n + m = 5n - 5m
Add 5m to both sides
n + 6m = 5n
Subtract n from both sides
6m = 4n
Divide both sides by 4
1.5m = n
Divide both sides by m
1.5 = n/m
or n/m = 1.5. This is the ratio of the larger number to the smaller.