$a)$   $4a=4\cdot$ $\frac{3}{4}=3$

$b)$

$c)$ $2a+b=2\cdot 1\frac{1}{2}+3={\sout{2}}^1\cdot \frac{3}{{\sout{2}}^1}+3=3+3=6$

$d)$ $\frac{1}{2}h=\frac{1}{{\sout{2}}^1}\cdot {\sout{6}}^3=3$

$e)$ $m-1\frac{1}{2}=4\frac{1}{6}-1\frac{1}{2}=4\frac{1}{6}-1\frac{3}{6}=3\frac{7}{6}-1\frac{3}{6}=2\frac{4}{6}=2\frac{2}{3}$

$f)$ $3b+2\frac{5}{6}=3\cdot 1\frac{1}{9}+2\frac{5}{6}={\sout{3}}^1\cdot \frac{10}{{\sout{9}}^3}+2\frac{5}{6}=$ $3\frac{1}{3}+2\frac{5}{6}=3\frac{2}{6}+2\frac{5}{6}=5\frac{7}{6}=6\frac{1}{6}$