648=x2-3x

Solution for 648=x2-3x equation:

648=x2-3x

We move all terms to the left:

648-(x2-3x)=0

We add all the numbers together, and all the variables

-(+x^2-3x)+648=0

We get rid of parentheses

-x^2+3x+648=0

We add all the numbers together, and all the variables

-1x^2+3x+648=0

a = -1; b = 3; c = +648;
Δ = b2-4ac
Δ = 32-4·(-1)·648
Δ = 2601
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2601}=51$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-51}{2*-1}=\frac{-54}{-2}
=+27
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+51}{2*-1}=\frac{48}{-2}
=-24
$