The value of a certain fraction becomes 1/5 if one is added to its numerator. If one is taken from its denominator, its value becomes 1/7. Find the fraction by setting up a pair of simultaneous equations and solving them

1 answer

(n+1)/d = 1/5
n/(d-1) = 1/7

5(n+1) = d
7n = d-1

5n - d = -5
7n - d = -1

2n = 4
n=2
d=15

Check:
n/d = 2/15

3/15 = 1/5
2/14 = 1/7