Question

Factor completely 2x2 – X – 4.
(3x - 1)(x + 4)
(3x + 4)(x - 1)
(3x − 2)(x + 2)
-
(3x – 4)(x + 1)
-

Answer 1

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

$x = \frac{ - ( - 1) + \sqrt{1 - 4(2)( - 4)} }{2(2)} = \frac{1 + \sqrt{33} }{4}$

$x = \frac{1 - \sqrt{33} }{4}$

$(x - \frac{1 + \sqrt{33} }{4} )(x - \frac{1 - \sqrt{33} }{4} )$

$(4x - 1 - \sqrt{33} )(4x - 1 + \sqrt{33} )$