Simplify by removing the factor of 1

Question

5y -20 / 5y

Answer 1

5 y - 20 / 5 y =

5 y - 4 * 5 / 5 y =

5 y - 4 / y =

( 5 y * y - 4 ) / y =

( 5 y ^ 2 - 4 ) / y

Answer 2

I assume you mean

(5y-20)/(5y)
then
= 5(y-4)/(5y)

= (y-4)/y