## Key Concepts

• Commutative Properties
• If $a,b$ are real numbers, then $a+b=b+a$
• If $a,b$ are real numbers, then $a\cdot b=b\cdot a$
• If $a,b,c$ are real numbers then $\left(a+b\right)+c=a+\left(b+c\right)$
• If $a,b,c$ are real numbers then $\left(a\cdot b\right)\cdot c=a\cdot \left(b\cdot c\right)$