Question 653021
<pre>
        {{{2/3}}} + {{{3k/4}}} = {{{71/12}}}

The LCD is 12, so multiply both sides by 12:

  12·{{{2/3}}} + 12·{{{3k/4}}} = 12·{{{71/12}}}

        8 + 9k = 71

            9k = 63

             k = 7

Edwin</pre>