Variables and Algebraic Expressions: Common denominators with variables

$\frac{1}{4}a+\frac{1}{3}x+\frac{2}{4}a+\frac{1}{8}+\frac{3}{8}=\text{?}$

$\frac{3}{4}a+\frac{1}{3}x+\frac{1}{2}$

$\frac{3}{4}+\frac{1}{8}m+\frac{2}{8}n+\frac{17}{8}m=\text{?}$

$\frac{3}{4}+2\frac{1}{4}m+\frac{1}{4}n$

$\frac{x}{8}+\frac{31}{8}+\frac{x}{4}+\frac{1}{4}x+\frac{y}{8}=\text{?}$

$3\frac{7}{8}+\frac{5}{8}x+\frac{y}{8}$

$\frac{1}{4a}+\frac{1}{2a}+\frac{x}{3}+\frac{4}{3}b+\frac{2}{3}x=\text{?}$

$\frac{3}{4a}+x+\frac{4}{3}b$

$\frac{3}{8}a+\frac{14}{9}b+1\frac{1}{9}b+\frac{6}{8}a=\text{?}$

$1\frac{1}{8}a+2\frac{2}{3}b$