1.Expand the following expression:
(a + b)²

Answer:
= a² + 2ab + b²


2. Expand the following expression:
(a + b)⁴

Answer:
= a⁴ + 4a³b + 6a²b² + 4ab³ + b⁴


3. Expand the following expression:
(a - b)⁸

Answer:
= a⁸ - 8a⁷b + 28a⁶b² - 56a⁵b³ + 70a⁴b⁴ - 56a³b⁵ + 28a²b⁶ - 8ab⁷ + b⁸


4. What do we use to determine the coefficient of the (k + 1)st term in the expansion of (a + b)ⁿ.

Answer:
Factorial notation. In this case we use n factorial (n!) if n is any positive integer.


5. What does 0! equal?


Answer: 1