Answer:
4/5
Explanation:
the numerator of fraction is 1 less than its denominator. If the numerator is increased by 4 and the denominator is increased by 5, the new fraction becomes equivalent to 4/5. what is the original fraction?
Let n = numerator
d = denominator
n = d - 1

=
=

cross multiply
5(d + 3) = 4(d + 5)
5d + 15 = 4d + 20
d = 5
n = d - 1
5 - 1 = 4
original fraction 4/5