Question 179129
{{{n + 3/4}}}
{{{n = 1/3}}}
The least common multiple is {{{3*4 = 12}}}
If you have a computer, helpwithfractions.com is good
You can multiply the top and bottom of any fraction
by the same number without changing the fraction
{{{n = 1/3}}}
{{{n = (4/4)*(1/3)}}}
{{{n = 4/12}}}
This is the same as 
{{{n = 1*(1/3)}}} and doesn't change the fraction
Also, {{{3/4 = (3/3)*(3/4)}}}
{{{3/4 = 9/12}}} again, I have not changed the fraction
{{{n + 3/4 = n + 9/12}}} 
and I already determined
{{{n = 4/12}}}
{{{4/12 + 9/12 = 13/12}}} or 1 1/12 answer
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And n = 1 3/4
Note that {{{1 = 4/4}}}, so I can rewrite it as
1 3/4 = {{{4/4 + 3/4 = 7/4}}}
{{{n + 3/4 = 7/4 + 3/4}}}
{{{7/4 + 3/4 = 10/4}}}, or 2 1/2 answer
I hope this helps you to proceed