Question

PRACTISE NOW 6
Factorise each of the following expressions completely.
Th
(a) x2 + 8x + 7
(c) x2 + x - 2
(b) r- - 11x + 28
(d) r2 - 7x -8
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Answer 1

Answer:

(a) (x + 1)(x + 7)

(c) (x + 2)(x - 1)

(b) (x - 4)(x - 7)

(d) (x + 1)(x - 8)

Step-by-step explanation:

(a)

$x^{2} + 8x + 7\\ = x^{2} + x + 7x + 7 \\= (x + 1)(x + 7)$

(c)

$x^{2} + x - 2\\= x^{2} + 2x - x - 2\\=(x + 2)(x - 1)$

(b)

$x^{2} - 11x + 28\\= x^{2} - 4x - 7x + 28 \\= (x - 4)(x - 7)$

(d)

$x^{2} - 7x - 8\\= x^{2} + x - 8x - 8\\= (x + 1)(x - 8)$