Question

2x^2+x+4
find using completing the square method .
plz plz answer​

Answer 1

Answer:

$x = \frac{-1±\sqrt{-7}}{2}$

Step-by-step explanation:

2x²+x+4=0

=> 2x²+x = -4

/* divide each term by 2,we get

$\implies x^{2}+\frac{x}{2}=-2$

$\implies x^{2}+2\times x \times \frac{1}{2}=-2$

$\implies x^{2}+2\times x \times \frac{1}{2}+\left(\frac{1}{2}\right)^{2}=-2 + \left(\frac{1}{2}\right)^{2}$

$\implies \left(x+\frac{1}{2}\right)^{2}=-2+\frac{1}{4}$

$\implies \left(x+\frac{1}{2}\right)^{2}=\frac{-8+1}{4}$

$\implies \left(x+\frac{1}{2}\right)^{2}=\frac{-7}{4}$

$\implies \left(x+\frac{1}{2}\right)=±\sqrt{\frac{-7}{4}}$

$\implies x =-\frac{1}{2}±\frac{\sqrt{-7}}{2}$

$\implies x = \frac{-1±\sqrt{-7}}{2}$

Therefore,

$x = \frac{-1±\sqrt{-7}}{2}$

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