3 1/2 + 2 6/7

Good try forest304.  (S)he mean what is 3 1/2+ 2 6/7 as fractions.  The answer is 6 5/14

I'm not sure what you are asking, so here are two possibilities:

3 x 1/2 + 2 x 6/7

=1.5 + 1.7

=2.2

If you meant

3.5 + 2.86

approx = 6.36