66x^2-168x-90=0

Solution for 66x^2-168x-90=0 equation:

66x^2-168x-90=0

a = 66; b = -168; c = -90;
Δ = b2-4ac
Δ = -1682-4·66·(-90)
Δ = 51984
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{51984}=228$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-168)-228}{2*66}=\frac{-60}{132}
=-5/11
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-168)+228}{2*66}=\frac{396}{132}
=3
$