Question

The numerator of a fraction is two less than its denominator. When both numerator and denominator are increased by 3, the fraction is incre 
ased by 3/20. Find the original fraction.

Answer 1

(n-2)/n

(n+1)/(n+3) = (n-2)/n + 3/20

multiply both sides by 20 n(n+3)
20 n(n+1) = 20(n+3)(n-2) + 3n(n+3)
20n^2 + 20n =20(n^2 +n-6) +3n^2 + 9 n
20n^2 + 20n = 20n^2 +20n -120 + 3n^2 + 9n
solve quadratic for n
then do
(n-2)/n