p^2+1.8p-1=0

Solution for p^2+1.8p-1=0 equation:

p^2+1.8p-1=0

a = 1; b = 1.8; c = -1;
Δ = b2-4ac
Δ = 1.82-4·1·(-1)
Δ = 7.24
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1.8)-\sqrt{7.24}}{2*1}=\frac{-1.8-\sqrt{7.24}}{2}
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1.8)+\sqrt{7.24}}{2*1}=\frac{-1.8+\sqrt{7.24}}{2}
$