Factorise `49x^(2) - 16y^(2)`. – InterviewSolution

1.	Factorise `49x^(2) - 16y^(2)`.
Answer» Let a = 7x and b = 4y . Using the identify `a^(2) - b^(2) = (a-b) (a +b)` , we have `49x^(2) - 16y^(2) = (7x)^(2) - (4y)^(2) = (7x-4y) (7x + 4y)`.

Discussion

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An equation which is true for all real values of its variables is called an identify .
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