Question

factorise
$3x^3 - x - 4$
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Answer 1

Answer:

${3x}^{2} - x - 4 \\ \\ {3x}^{2} - 4x + 3x - 4 = 0\\ \\ 3x(x - 4) + 3(x - 4) \\ \\ (3x + 3)(x - 4) = 0 \\ \\ 3x + 3 = 0 \: \: or \: \: x - 4 = 0 \\ \\ x = \frac{ - 3}{3} \: \: or \: \: x = 4 \\ \\ x = - 1 \: \: or \: \: x = 4$

hope it helps you