Simplify \frac{3}{(x+2)} -\frac{2}{(x-1)}

STEP 1: Recall what are polynomials
STEP 2: Recall what are fractions
https://www.ducksters.com/kidsmath/fractions_introduction.php
STEP 3: Recall what is an expression
http://home.avvanta.com/~math/def2.cgi?t=expression
STEP 4: Recall what is an rational expression
http://home.avvanta.com/~math/def2.cgi?t=expression
STEP 5: Recall subtracting rational expressions with unlike denominators
STEP 6: Simplify
\frac{3}{(x+2)} - \frac{2}{(x-1)}
\frac{3(x-1)-2(x+2)}{(x+2)(x-1)}
\frac{ 3x -3 -2x -4}{(x+2)(x+1)}
\frac{x-7}{(x+2)(x+1)}