X(x-3)-1890=0

Solution for X(x-3)-1890=0 equation:

X(X-3)-1890=0

We multiply parentheses

X^2-3X-1890=0

a = 1; b = -3; c = -1890;
Δ = b2-4ac
Δ = -32-4·1·(-1890)
Δ = 7569
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7569}=87$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3)-87}{2*1}=\frac{-84}{2}
=-42
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+87}{2*1}=\frac{90}{2}
=45
$