# Evaluate the Following Using Identities: (399)2 - Mathematics

Evaluate the following using identities:

(399)2

#### Solution

In the given problem, we have to evaluate expressions by using identities.

Given (399)^2

We can write(399)^2 " as " (400 - 1)^2

We shall use the Identity (x - y)^2 - 2xy + y^2

Where x = 400, y = 1

By applying in identity we get

(400 - 1)^2 = (400)^2 - 2 xx 400 xx 1 + (1)^2

= 400 xx 400 - 800 +  1

= 16000 - 800 + 1

=159201

Hence the value of (399)^2 is 159201

Is there an error in this question or solution?

#### APPEARS IN

RD Sharma Mathematics for Class 9
Chapter 4 Algebraic Identities
Exercise 4.1 | Q 2.1 | Page 7