-9x^2+48x-15=0

Solution for -9x^2+48x-15=0 equation:

-9x^2+48x-15=0

a = -9; b = 48; c = -15;
Δ = b2-4ac
Δ = 482-4·(-9)·(-15)
Δ = 1764
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1764}=42$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(48)-42}{2*-9}=\frac{-90}{-18}
=+5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(48)+42}{2*-9}=\frac{-6}{-18}
=1/3
$