x^2-3x=630

Solution for x^2-3x=630 equation:

x^2-3x=630

We move all terms to the left:

x^2-3x-(630)=0

a = 1; b = -3; c = -630;
Δ = b2-4ac
Δ = -32-4·1·(-630)
Δ = 2529
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{2529}=\sqrt{9*281}=\sqrt{9}*\sqrt{281}=3\sqrt{281}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3)-3\sqrt{281}}{2*1}=\frac{3-3\sqrt{281}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+3\sqrt{281}}{2*1}=\frac{3+3\sqrt{281}}{2}
$