2400=2x+2x(0.33x)

Solution for 2400=2x+2x(0.33x) equation:

2400=2x+2x(0.33x)

We move all terms to the left:

2400-(2x+2x(0.33x))=0

We add all the numbers together, and all the variables

-(2x+2x(+0.33x))+2400=0


We calculate terms in parentheses: -(2x+2x(+0.33x)), so:

2x+2x(+0.33x)

We multiply parentheses

0x^2+2x

We add all the numbers together, and all the variables

x^2+2x

Back to the equation:

-(x^2+2x)


We get rid of parentheses

-x^2-2x+2400=0

We add all the numbers together, and all the variables

-1x^2-2x+2400=0

a = -1; b = -2; c = +2400;
Δ = b2-4ac
Δ = -22-4·(-1)·2400
Δ = 9604
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9604}=98$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-98}{2*-1}=\frac{-96}{-2}
=+48
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+98}{2*-1}=\frac{100}{-2}
=-50
$