[tex]\frac{1}{6} + \frac{1}{12}[/tex]
We know that:
[tex]\frac{a}{b} + \frac{c}{d} = \frac{a.d + b.c}{bd}[/tex]
So,
[tex]\frac{1}{6} + \frac{1}{12} = \frac{1.12+6.1}{6.12}[/tex]
[tex]\frac{12+6}{72}[/tex]
[tex]\frac{18}{72}[/tex]
[tex]\frac{9}{36}[/tex]
[tex]\frac{3}{12}[/tex]
[tex]\frac{1}{4}[/tex]