.638x^2+6.671x+627.619=890,000

Solution for .638x^2+6.671x+627.619=890,000 equation:

.638x^2+6.671x+627.619=890.000

We move all terms to the left:

.638x^2+6.671x+627.619-(890.000)=0

We add all the numbers together, and all the variables

.638x^2+6.671x+627.619-890=0

We add all the numbers together, and all the variables

.638x^2+6.671x-262.381=0

a = .638; b = 6.671; c = -262.381;
Δ = b2-4ac
Δ = 6.6712-4·.638·(-262.381)
Δ = 714.098553
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6.671)-\sqrt{714.098553}}{2*.638}=\frac{-6.671-\sqrt{714.098553}}{1.276}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6.671)+\sqrt{714.098553}}{2*.638}=\frac{-6.671+\sqrt{714.098553}}{1.276}
$