30x2+25x-20=0

Solution for 30x2+25x-20=0 equation:

30x^2+25x-20=0

a = 30; b = 25; c = -20;
Δ = b2-4ac
Δ = 252-4·30·(-20)
Δ = 3025
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3025}=55$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-55}{2*30}=\frac{-80}{60}
=-1+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+55}{2*30}=\frac{30}{60}
=1/2
$