300=(2x+1)*x

Solution for 300=(2x+1)*x equation:

300=(2x+1)*x

We move all terms to the left:

300-((2x+1)*x)=0


We calculate terms in parentheses: -((2x+1)*x), so:

(2x+1)*x

We multiply parentheses

2x^2+x

Back to the equation:

-(2x^2+x)


We get rid of parentheses

-2x^2-x+300=0

We add all the numbers together, and all the variables

-2x^2-1x+300=0

a = -2; b = -1; c = +300;
Δ = b2-4ac
Δ = -12-4·(-2)·300
Δ = 2401
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2401}=49$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-49}{2*-2}=\frac{-48}{-4}
=+12
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+49}{2*-2}=\frac{50}{-4}
=-12+1/2
$