## Key Concepts

• If $a,b$, and $c$ are numbers where $c\ne 0$ , then ${\Large\frac{a}{c}}+{\Large\frac{b}{c}}={\Large\frac{a+c}{c}}$ .
• If $a,b$, and $c$ are numbers where $c\ne 0$ , then ${\Large\frac{a}{c}}-{\Large\frac{b}{c}}={\Large\frac{a-b}{c}}$ .