Question

factorise 1 + 2 a b - a square - b square

Answer 1

$1 + 2ab - {a}^{2} - {b}^{2} \\ = 1 - ( {a}^{2} - 2ab + {b}^{2} ) \\ = 1 - (a - b)^{2} \\ = {1}^{2} - {(a - b)}^{2} \\ = (1 + a - b)(1 - a + b)$
hope it helps....

Answer 2

hey mate here is your answer

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