How do you solve $x^{2} = x + 2$ $x^2 = x + 2$ ?

Question

1006 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-06-26T21:49:06

$x = 2 or x = - 1$ $x= 2 or x=-1$

It is a quadratic equation, so make it equal to 0.

$x^{2} - x - 2 = 0 factorise$ $x^2 -x -2 = 0 " factorise"$

Find factors of 2 which subtract to give 1.
As 2 is a prime number it only has factors 2 and 1.

The signs will be different, there must be more negatives.

$(x - 2) (x + 1) = 0$ $(x-2)(x+1)=0$

If $x - 2 = 0$ $x-2 = 0$ , then x = 2
If $x + 1 = 0$ $x+1 = 0$ , then x = -1

How do you solve x^2 = x + 2 x2=x+2x^2 = x + 2 ?