P(x)=x2+2x

Solution for P(x)=x2+2x equation:

(P)=P2+2P

We move all terms to the left:

(P)-(P2+2P)=0

We add all the numbers together, and all the variables

-(+P^2+2P)+P=0

We get rid of parentheses

-P^2-2P+P=0

We add all the numbers together, and all the variables

-1P^2-1P=0

a = -1; b = -1; c = 0;
Δ = b2-4ac
Δ = -12-4·(-1)·0
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$P_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$P_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$P_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-1}{2*-1}=\frac{0}{-2}
=0
$
$P_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+1}{2*-1}=\frac{2}{-2}
=-1
$