4800=2(4800-280x-4x2)

Solution for 4800=2(4800-280x-4x2) equation:

4800=2(4800-280x-4x^2)

We move all terms to the left:

4800-(2(4800-280x-4x^2))=0


We calculate terms in parentheses: -(2(4800-280x-4x^2)), so:

2(4800-280x-4x^2)

We multiply parentheses

-8x^2-560x+9600

Back to the equation:

-(-8x^2-560x+9600)


We get rid of parentheses

8x^2+560x-9600+4800=0

We add all the numbers together, and all the variables

8x^2+560x-4800=0

a = 8; b = 560; c = -4800;
Δ = b2-4ac
Δ = 5602-4·8·(-4800)
Δ = 467200
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{467200}=\sqrt{6400*73}=\sqrt{6400}*\sqrt{73}=80\sqrt{73}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(560)-80\sqrt{73}}{2*8}=\frac{-560-80\sqrt{73}}{16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(560)+80\sqrt{73}}{2*8}=\frac{-560+80\sqrt{73}}{16}
$