The denominator of a fraction is 4 more than the numerator. If 4 is added to the numerator and 7 is

The denominator of a fraction is 4 more than the numerator. If 4 is added to the numerator and 7 is added to the denominator, the value of the fraction is 1/2. Find the original fraction.

Let the original fraction be n/d.

We're given:

1. d = n + 4
2. (n + 4) / (d + 7) = 1/2

Cross multiply Equation 2:
2(n + 4) = d + 7
2n + 8 = d + 7

Now substitute equation (1) into tihs:
2n + 8 = (n + 4) + 7
2n + 8 = n + 11

Type this equation into our search engine, and we get:
n = 3

This means from equation (1), that:
d = 3 + 4
d = 7

So our original fraction n/d = 3/7