Use the direct method to evaluate : (ab+x^2) (ab−x^2) - Vidyadip

Question

Use the direct method to evaluate : $(ab+x^2) (ab−x^2)$

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Answer

$(a+b) (a−b) $
$= a^2 − b^2(ab+x^2) (ab−x^2) $
$= (ab)^2 − (x^2)^2$
$= a^2b^2 − x^4$

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