2x^2+6x=280

Solution for 2x^2+6x=280 equation:

2x^2+6x=280

We move all terms to the left:

2x^2+6x-(280)=0

a = 2; b = 6; c = -280;
Δ = b2-4ac
Δ = 62-4·2·(-280)
Δ = 2276
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:

$\sqrt{\Delta}=\sqrt{2276}=\sqrt{4*569}=\sqrt{4}*\sqrt{569}=2\sqrt{569}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-2\sqrt{569}}{2*2}=\frac{-6-2\sqrt{569}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+2\sqrt{569}}{2*2}=\frac{-6+2\sqrt{569}}{4}
$