10p^2-17p-20=0

Solution for 10p^2-17p-20=0 equation:

10p^2-17p-20=0

a = 10; b = -17; c = -20;
Δ = b2-4ac
Δ = -172-4·10·(-20)
Δ = 1089
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1089}=33$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-17)-33}{2*10}=\frac{-16}{20}
=-4/5
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-17)+33}{2*10}=\frac{50}{20}
=2+1/2
$