x(325=5x)=4000

Solution for x(325=5x)=4000 equation:

x(325=5x)=4000

We move all terms to the left:

x(325-(5x))=0

We add all the numbers together, and all the variables

x(-5x+325)=0

We multiply parentheses

-5x^2+325x=0

a = -5; b = 325; c = 0;
Δ = b2-4ac
Δ = 3252-4·(-5)·0
Δ = 105625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{105625}=325$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(325)-325}{2*-5}=\frac{-650}{-10}
=+65
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(325)+325}{2*-5}=\frac{0}{-10}
=0
$