(20 + n)¢
With Company X, it costs 35¢ to connect and then 5¢ for each minute.
So, for n minutes of calling the company X charges, C(x) = (35 + 5n)¢
Again, With Company Y, it costs 15¢ to connect and then 4¢ for each minute.
So, for n minutes of calling the company Y charges, C(y) = (15 + 4n)¢.
therefore, the company Y charges for n minutes of calling less than company x is
[(35 + 5n) - (15 + 4n)]¢ = (20 + n)
answer - (20 + n) ¢
hope this helps!!