5x^2+20x-141=0

Solution for 5x^2+20x-141=0 equation:

5x^2+20x-141=0

a = 5; b = 20; c = -141;
Δ = b2-4ac
Δ = 202-4·5·(-141)
Δ = 3220
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{3220}=\sqrt{4*805}=\sqrt{4}*\sqrt{805}=2\sqrt{805}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-2\sqrt{805}}{2*5}=\frac{-20-2\sqrt{805}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+2\sqrt{805}}{2*5}=\frac{-20+2\sqrt{805}}{10}
$