Question

1. Factorise
(x^2- 4x + 4) - 81
​

Answer 1

Answer:

x² - 4x - 77

x² - 11x + 7x - 77

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

(x - 11)(x + 7)

Therefore, x = 11 and -7 .

Answer 2

Answer:

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

$= ({x}^{2} - 2x - 2x + 4) - 81$

$= x(x - 2) - 2(x - 2) - 81$

$= [(x - 2)(x - 2)] - 81$

$= {(x - 2)}^{2} - {9}^{2}$

$= (x - 2 + 9)(x - 2 - 9)$

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