2y^2-y-280=0

Solution for 2y^2-y-280=0 equation:

2y^2-y-280=0

We add all the numbers together, and all the variables

2y^2-1y-280=0

a = 2; b = -1; c = -280;
Δ = b2-4ac
Δ = -12-4·2·(-280)
Δ = 2241
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{2241}=\sqrt{9*249}=\sqrt{9}*\sqrt{249}=3\sqrt{249}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-3\sqrt{249}}{2*2}=\frac{1-3\sqrt{249}}{4}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+3\sqrt{249}}{2*2}=\frac{1+3\sqrt{249}}{4}
$