Question

Find the value of (132^2-122^2). A) 1 B) 25 C) 313 D) 34336​

Answer 1

Solution

(132² - 122²)

= (132²) - (122²)

Using identity a² - b² = (a - b) (a + b)

= (132 - 122) (132 + 122)

= (10) (254)

= 10 × 254

= 2540.

More identities to know

• (a + b)² = a² + 2ab + b²

• (a - b)² = a² - 2ab + b²

• a² + b² = (a + b)² - 2ab

• 2ab = (a + b)² - (a² + b²)

• a² + b² = (a - b)² + 2ab