X2+4x=621

Solution for X2+4x=621 equation:

X2+4X=621

We move all terms to the left:

X2+4X-(621)=0

We add all the numbers together, and all the variables

X^2+4X-621=0

a = 1; b = 4; c = -621;
Δ = b2-4ac
Δ = 42-4·1·(-621)
Δ = 2500
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2500}=50$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-50}{2*1}=\frac{-54}{2}
=-27
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+50}{2*1}=\frac{46}{2}
=23
$