0=-66x^2+50x+4

Solution for 0=-66x^2+50x+4 equation:

0=-66x^2+50x+4

We move all terms to the left:

0-(-66x^2+50x+4)=0

We add all the numbers together, and all the variables

-(-66x^2+50x+4)=0

We get rid of parentheses

66x^2-50x-4=0

a = 66; b = -50; c = -4;
Δ = b2-4ac
Δ = -502-4·66·(-4)
Δ = 3556
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:

$\sqrt{\Delta}=\sqrt{3556}=\sqrt{4*889}=\sqrt{4}*\sqrt{889}=2\sqrt{889}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-50)-2\sqrt{889}}{2*66}=\frac{50-2\sqrt{889}}{132}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-50)+2\sqrt{889}}{2*66}=\frac{50+2\sqrt{889}}{132}
$