Question

expand the following using the identities (3a+b)^2​

Answer 1

ANSWER:

• Value of above expression is 9a²+b²+6ab

GIVEN:

• (3a+b)²

TO FIND:

• Value of the above expression.

SOLUTION:

Formula:

=> (a+b)² = a²+b²+2ab

By using this formula we can expand the expression.

= (3a+b)²

= (3a)² +(b)²+2(3a)(b)

= 9a²+b²+6ab

NOTE:

some important formulas:

• (a+b)² = a²+b²+2ab
• (a-b)² = a²+b²-2ab
• (a+b)³ = a³+b³+3ab(a+b)
• (a-b)³ = a³-b³-3ab(a-b)
• (a³+b³) = (a+b)(a²+b²-ab)
• (a³-b³) = (a-b)(a²+b³+ab)
• (a+b)² = (a-b)² +4ab
• (a-b)² = (a+b)² -4ab