0=x(4200-60x)

Solution for 0=x(4200-60x) equation:

0=x(4200-60x)

We move all terms to the left:

0-(x(4200-60x))=0

We add all the numbers together, and all the variables

-(x(-60x+4200))+0=0

We add all the numbers together, and all the variables

-(x(-60x+4200))=0


We calculate terms in parentheses: -(x(-60x+4200)), so:

x(-60x+4200)

We multiply parentheses

-60x^2+4200x

Back to the equation:

-(-60x^2+4200x)


We get rid of parentheses

60x^2-4200x=0

a = 60; b = -4200; c = 0;
Δ = b2-4ac
Δ = -42002-4·60·0
Δ = 17640000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{17640000}=4200$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4200)-4200}{2*60}=\frac{0}{120}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4200)+4200}{2*60}=\frac{8400}{120}
=70
$