Question
Factorise $: 15x^2 - x - 28$
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Answer
$15x^2 - x - 28$
$= 15x^2 + 20x - 21x - 28$
$= 5x(3x + 4) - 7(3x + 4)$
$= (3x + 4)(5x - 7)$
$= 15x^2 + 20x - 21x - 28$
$= 5x(3x + 4) - 7(3x + 4)$
$= (3x + 4)(5x - 7)$
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