Y=-5.25x^2+63x+5

Solution for Y=-5.25x^2+63x+5 equation:

=-5.25Y^2+63Y+5

We move all terms to the left:

-(-5.25Y^2+63Y+5)=0

We get rid of parentheses

5.25Y^2-63Y-5=0

a = 5.25; b = -63; c = -5;
Δ = b2-4ac
Δ = -632-4·5.25·(-5)
Δ = 4074
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{-(-63)-\sqrt{4074}}{2*5.25}=\frac{63-\sqrt{4074}}{10.5}
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-63)+\sqrt{4074}}{2*5.25}=\frac{63+\sqrt{4074}}{10.5}
$