Perform the operations and simplify

Explanation

Subtract the numerators and write the difference over the common denominator 25

$\frac{18}{25} - \frac{2}{25} - \frac{1}{25} = \frac{18 - 2 - 1}{25}$

This fraction can be simplified

$= \frac{15}{25}$

To simplify, factor 15 as 3 • 5 and 25 as 5 • 5.  Then remove the common factor of 5 from the numerator and denominator.

$\require{cancel} = \frac{3 \cdot \cancel{5}^1}{\cancel{5}_1 \cdot 5}$

Multiply the remaining factors in the numerator: 3 • 1 = 3.  Multiply the remaining factors in the denominator: 1 • 5 = 5

$= \frac35$