-30x^2-69x+15=0

Solution for -30x^2-69x+15=0 equation:

-30x^2-69x+15=0

a = -30; b = -69; c = +15;
Δ = b2-4ac
Δ = -692-4·(-30)·15
Δ = 6561
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6561}=81$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-69)-81}{2*-30}=\frac{-12}{-60}
=1/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-69)+81}{2*-30}=\frac{150}{-60}
=-2+1/2
$