[tex] \frac{a}{b} * \frac{b}{c} * \frac{c}{d} * \frac{d}{e}= \frac{a}{e} [/tex]
lets rewrite the equation so as to better understand why this equation is true..
[tex]\frac{a}{b} * \frac{b}{c} * \frac{c}{d} * \frac{d}{e}= \frac{abcd}{bcde}= \frac{a}{e} * \frac{b}{b} * \frac{c}{c} * \frac{d}{d}
[/tex]
If both the numerator and the denominator are the same in a fraction, then that fraction is equivalent to 1. So we can rewrite the equation as such.
[tex]\frac{a}{e} * 1 * 1 *1= \frac{a}{e} [/tex]
Since the b's, c's and d's cancel out, a/b*b/c*c/d*d/e=a/e
