x(x-2)=195

Solution for x(x-2)=195 equation:

x(x-2)=195

We move all terms to the left:

x(x-2)-(195)=0

We multiply parentheses

x^2-2x-195=0

a = 1; b = -2; c = -195;
Δ = b2-4ac
Δ = -22-4·1·(-195)
Δ = 784
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{784}=28$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-28}{2*1}=\frac{-26}{2}
=-13
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+28}{2*1}=\frac{30}{2}
=15
$