Answer
In order to simplify a fraction to its lowest terms you have to find the lowest common factor of that the numerator and denominator share. Once you find the lowest common factor you divide both the numerator and denominator by that factor and you have the lowest terms of your original fraction.
$\frac{15}{5}$ lowest common factor is 5
$\frac{15\div5}{5\div5 }$ = $\frac{3}{1}$ = 3
3 is $\frac{15}{5}$ in its lowest form
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