4x(2x-200)=0

Solution for 4x(2x-200)=0 equation:

4x(2x-200)=0

We multiply parentheses

8x^2-800x=0

a = 8; b = -800; c = 0;
Δ = b2-4ac
Δ = -8002-4·8·0
Δ = 640000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{640000}=800$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-800)-800}{2*8}=\frac{0}{16}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-800)+800}{2*8}=\frac{1600}{16}
=100
$