280=x^2+38x

Solution for 280=x^2+38x equation:

280=x^2+38x

We move all terms to the left:

280-(x^2+38x)=0

We get rid of parentheses

-x^2-38x+280=0

We add all the numbers together, and all the variables

-1x^2-38x+280=0

a = -1; b = -38; c = +280;
Δ = b2-4ac
Δ = -382-4·(-1)·280
Δ = 2564
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:

$\sqrt{\Delta}=\sqrt{2564}=\sqrt{4*641}=\sqrt{4}*\sqrt{641}=2\sqrt{641}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-38)-2\sqrt{641}}{2*-1}=\frac{38-2\sqrt{641}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-38)+2\sqrt{641}}{2*-1}=\frac{38+2\sqrt{641}}{-2}
$