Question 205930
The denominator of a fraction is 4 less than the numerator.
d = n - 4
:
 If the denominator is doubled and the numerator is increased by 6, the sum of 
the original fraction and the new one is 3.
{{{((n+6))/(2d)}}} + {{{n/d}}} = 3
Multiply equation by 2d, results:
(n + 6) + 2n = 3(2d)
:
3n + 6 = 6d
Replace d with (n-4)
3n + 6 = 6(n-4)
:
3n + 6 = 6n - 24
:
6 + 24 = 6n - 3n
:
30 = 3n
n = {{{30/3}}}
n = 10 is the numerator
then
d = 10 - 4 
d = 6 is the denominator
:
{{{10/6}}} is the original fraction.
:
:
Prove this in the statement:
"the denominator is doubled and the numerator is increased by 6, the sum of 
the original fraction and the new one is 3.
{{{16/12}}} + {{{10/6}}} = 
{{{16/12}}} + {{{20/12}}} = {{{36/12}}} = 3