Question

factorise(x^2-4x+4)-81
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Answer 1

Answer:

$x { }^{2} - 4x + 4 - 81$

$x {}^{2} - 4x - 77$

$x {}^{2} + 7x - 11x - 77$

$x(x + 7) - 11(x + 7)$

$(x + 7)(x - 11)$

Answer 2

$( {x}^{2} + 4 - 4x) - 81 \\ (x - 2) {}^{2} - 81 \\ (x - 2 + 9)(x - 2 - 9) \\ (x + 7)(x - 11)$