Question

2 X square + X - 4 is equal to zero find its root by the method of completing square ​

Answer 1

Hey

$2x {}^{2} + x - 4 = 0 \\ \\dividing \: the \: whole \: equation \: by \: 2 \\ \\ = > x {}^{2} + \frac{x}{2} - 2 = 0 \\ \\ = > x {}^{2} + \frac{x}{2} = 2 \\ \\ adding \: \frac{1}{4} {}^{2} \: on \: both \: sides \\ = > (x) {}^{2} + 2( \frac{1}{4} )x + ( \frac{1}{4} ) {}^{2} = 2 + ( \frac{1}{4}) {}^{2} \\ \\ = > (x + \frac{1}{4} ) {}^{2} = 2 + \frac{1}{16 } \\ \\ = > (x + \frac{1}{4} ) {}^{2} = \frac{33}{16} \\ \\ = > x + \frac{1}{4} = + \frac{ \sqrt{33} }{4} \: or \: - \frac{ \sqrt{33} }{4} \\ \\ = > x = \frac{ \sqrt{33} - 4 }{4} \: or \: \frac{ - \sqrt{33} - 4 }{4}$

I hope it helps you!!!