Question

Using the quadratic formula to solve x2 + 20 = 2x, what are the values of x?

Answer 1

by Quadratic formula , $x^2 + 20 = 2x$ , values of x are $x = 1 \pm (1)i\sqrt{19}}$ . None of mentioned options are correct according to question!

Step-by-step explanation:

Here we have , expression  x2 + 20 = 2x or , $x^2 + 20 = 2x$ .

We know that Quadratic formula is :

$x = \frac{-b \pm \sqrt{b^{2}-4ac}}{2a}$

$x^2 + 20 = 2x$

⇒ $x^2-2x+20=0$

$a=1\\b=-2\\c=20$

Putting this value in equation $x = \frac{-b \pm \sqrt{b^{2}-4ac}}{2a}$ :

⇒ $x = \frac{-b \pm \sqrt{b^{2}-4ac}}{2a}$

⇒ $x = \frac{-(-2) \pm \sqrt{(-2)^{2}-4(1)(20)}}{2(1)}$

⇒ $x = \frac{2 \pm \sqrt{4-80}}{2}$

⇒ $x = (\frac{2 \pm 2i\sqrt{19}}{2})$

⇒ $x = 1 \pm (1)i\sqrt{19}}$

Therefore , by Quadratic formula , $x^2 + 20 = 2x$ , values of x are $x = 1 \pm (1)i\sqrt{19}}$ . None of mentioned options are correct according to question!