Evaluate, Using (A + B)(A - B)= A2 - B2. 399 X 401

Evaluate, using (a + b)(a - b)= a² - b².
399 x 401

Sum

399 x 401
= (400 - 1) x (400 + 1)
= (400)² - (1)²
= 160000 - 1
= 159999.

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Chapter 4: Expansions - Exercise 4.1

Chapter 4 Expansions
Exercise 4.1 | Q 6.1

Expand the following, using suitable identity:

(3a – 7b – c)²

Give possible expression for the length and breadth of the following rectangle, in which their area is given:

Evaluate the following using identities:

(1.5x²− 0.3y²) (1.5x²+ 0.3y²)

Simplify (2x + p - c)² - (2x - p + c)²

Simplify the following expressions:

`(x^2 - x + 1)^2 - (x^2 + x + 1)^2`

The product (a + b) (a − b) (a² − ab + b²) (a² + ab + b²) is equal to

The product (x²−1) (x⁴ + x² + 1) is equal to

Use identities to evaluate : (998)²

Evaluate : (4a +3b)² - (4a - 3b)² + 48ab.

Using suitable identity, evaluate the following:

103³