Question

using identities, find the following product:
(7xy-2)(7xy+7)

please tell me the way to get the answer.

Its answer is this :-
$49{x}^{2} {y}^{2} + 35xy - 14$
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Answer 1

Answer:

(7xy-2)(7xy+7)

Step-by-step explanation:

using identities

(x+a)(x-b) = x^2 + x(a - b) - a b

(7 x y - 2) (7 x y + 7) = (7 x y)^2 + 7 x y (-2 + 7) - 2 x 7

                                =  79 x^2 y^2 + 35 x y - 14