Use the direct method to evaluate : (x+1) (x−1) - Vidyadip

Question

Use the direct method to evaluate : $(x+1) (x−1)$

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Answer

Note: $(a+b) (a−b) .$
$= a^2 − b^2(x+1) (x−1)$
$= (x)^2 − (1)^2$
$= x^2− 1$

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