Question 74279
Let n=numerator, d=denominator
{{{d=3n}}}"denominator of a fraction is (=) by 3 larger than the numerator
{{{(n+5)/d=5/4}}}If you add 5 to the numerator you get 5/4
{{{4(n+5)=5d}}}Multiply both sides by 4d
{{{4(n+5)=5(3n)}}}Plug in 3n for d
{{{4n+20=15n}}}Solve for n
{{{20=11n}}}
{{{n=20/11}}}
So the denominator is
{{{d=3(20/11)}}}
{{{d=60/11}}}
<p>
Check:
{{{((20/11)+5)/(60/11)}}}
{{{((20/11)+(55/11))/(60/11)}}}
{{{(75/11)/(60/11)}}}
{{{(75/cross(11))(cross(11)/60)}}}
{{{(75/60)}}}
{{{(75/60)*((1/15)/(1/15))}}}
{{{5/4}}}Works