Question

how do I cancel three or more fractions?

Answer 1

Well, it really depends by the case. You have any exercise in particular to show?
Here's an example:
\[\frac{a}{b^2} * \frac{b}{c} * \frac{b}{c}\]
\[\frac{a}{\cancel{b^2}} * \frac{\cancel{b}}{c} * \frac{\cancel{b}}{c}\] = \[\frac{a}{c^2}\]