Y=-5x^2-10x+4

Solution for Y=-5x^2-10x+4 equation:

=-5Y^2-10Y+4

We move all terms to the left:

-(-5Y^2-10Y+4)=0

We get rid of parentheses

5Y^2+10Y-4=0

a = 5; b = 10; c = -4;
Δ = b2-4ac
Δ = 102-4·5·(-4)
Δ = 180
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:

$\sqrt{\Delta}=\sqrt{180}=\sqrt{36*5}=\sqrt{36}*\sqrt{5}=6\sqrt{5}$
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-6\sqrt{5}}{2*5}=\frac{-10-6\sqrt{5}}{10}
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+6\sqrt{5}}{2*5}=\frac{-10+6\sqrt{5}}{10}
$