1. The problem is to simplify the expression $\frac{ab - bc}{b}$. 2. We start by factoring the numerator: $$ab - bc = b(a - c)$$ 3. Substitute the factored form back into the expression: $$\frac{b(a - c)}{b}$$ 4. Since $b \neq 0$, we can cancel $b$ in numerator and denominator: $$\frac{\cancel{b}(a - c)}{\cancel{b}} = a - c$$ 5. The simplified expression is $a - c$. This means the original expression reduces to the difference between $a$ and $c$ after factoring and canceling the common factor $b$.