2x(70-2x)=600

Solution for 2x(70-2x)=600 equation:

2x(70-2x)=600

We move all terms to the left:

2x(70-2x)-(600)=0

We add all the numbers together, and all the variables

2x(-2x+70)-600=0

We multiply parentheses

-4x^2+140x-600=0

a = -4; b = 140; c = -600;
Δ = b2-4ac
Δ = 1402-4·(-4)·(-600)
Δ = 10000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{10000}=100$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(140)-100}{2*-4}=\frac{-240}{-8}
=+30
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(140)+100}{2*-4}=\frac{-40}{-8}
=+5
$