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Question
Evaluate the following using identities:
(399)2
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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
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