starting with the denominator,
add up the two fractions, however since the denominators are not equal, you cant
so, you need to find the equivalent fractions that have the same denominator
a method of doing so if through "cross multiplication"
once you have combined that fraction
[tex]\frac{\frac{ A}{B}}{\frac{a}{b} } = \frac{A}{B}*\frac{ b}{a}=\frac{Ab}{Ba}[/tex]
