Question

Find square of 39 without multification

Answer 1

Step-by-step explanation:

[39]^2 = [40 - 1]^2

Using identity

[a-b]^2 = a^2 + b^2 - 2ab

=40^2 + 1^2 - 2 x 40 x 1

=1600 + 1 - 80

=1601 - 80

=1521

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Hope this helps.