I think these are meant to be mixed fractions and not multiplication.
\(3\frac{4}{6}+4\frac{5}{6}\)
Let's convert to fractions
3*6+4/6
4*6+5/6
Thus we have:
\(\frac{22}{6}+\frac{29}{6}\) The same denominator we add the numerator
\(\frac{22+29}{6}=\frac{51}{6}\) Now the asker may want it presented as a mixed number
We know that 6 can go
6*8=48 which is closest to 51
so
\(8\frac{3}{6}\)
Further, simplify
\(8\frac{1}{2}\) (This is equal to 17/2 , which is a simplified fraction of 51/6 if you are wondering)