9x2+30x-171=0

Solution for 9x2+30x-171=0 equation:

9x^2+30x-171=0

a = 9; b = 30; c = -171;
Δ = b2-4ac
Δ = 302-4·9·(-171)
Δ = 7056
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7056}=84$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30)-84}{2*9}=\frac{-114}{18}
=-6+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+84}{2*9}=\frac{54}{18}
=3
$