SaiBook.us Algebra

Example

Title: Expand binomials by using binomial theorem.

Grade: 9-a Lesson: S3-L3

Explanation: The best way to understand algebra is by looking at some examples. Take turns and read each example for easy understanding.

Examples:

1. Expand \$(6b + 1/b)^3\$.

Step 1a

Given binomial.

Explanation: Given binomail is \$(6b + 1/b)^3\$.

Step 1b

Exapnad binomail using algebraic identities.

Explanation:
Use algebraic identity \$(a + b)^3 = a^3 + b^3 + 3ab(a + b)\$ to expand given binomial.

\$(6b + 1/b)^3\$

\$=> (6b)^3 + (1/b)^3 + 3(6b)(1/b)(6b + 1/b) \$

\$=> 216b^3 + 1/b^3 + 18b(1/b)(6b + 1/b) \$

\$=> 216b^3 + 1/b^3 + 18cancelb^1 1/cancelb^1(6b + 1/b) \$

\$=> 216b^3 + 1/b^3 + 18(6b + 1/b) \$

\$=> 216b^3 + 1/b^3 + 108b + 18/b \$