Y=-2x^2-6x+56

Solution for Y=-2x^2-6x+56 equation:

=-2Y^2-6Y+56

We move all terms to the left:

-(-2Y^2-6Y+56)=0

We get rid of parentheses

2Y^2+6Y-56=0

a = 2; b = 6; c = -56;
Δ = b2-4ac
Δ = 62-4·2·(-56)
Δ = 484
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{484}=22$
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-22}{2*2}=\frac{-28}{4}
=-7
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+22}{2*2}=\frac{16}{4}
=4
$