2y2-y-90=0

Solution for 2y2-y-90=0 equation:

2y^2-y-90=0

We add all the numbers together, and all the variables

2y^2-1y-90=0

a = 2; b = -1; c = -90;
Δ = b2-4ac
Δ = -12-4·2·(-90)
Δ = 721
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-\sqrt{721}}{2*2}=\frac{1-\sqrt{721}}{4}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{721}}{2*2}=\frac{1+\sqrt{721}}{4}
$