Question

(3a-12) (3a+12)
solve using Identity​

Answer 1

Given:

(3a - 12) (3a + 12)

What to do?

We have to solve the expression using an identity.

How to do?

To solve this expression we will use the identity (a - b) (a + b) = a² - b² where a = 3a and b = 12.

Solution:

(3a - 12) (3a + 12)

Using the identity,

⇒ (a - b) (a + b) = a² - b²

Susbtitute the values,

⇒  3a² - 12²

Multiply 3a and 12 by its square,

⇒ 9a - 144

∴ So, the answer is 9a - 144.

Identity used:

• (a - b) (a + b) = a² - b²