X^2-3.2x-1.65=0

Solution for X^2-3.2x-1.65=0 equation:

X^2-3.2X-1.65=0

a = 1; b = -3.2; c = -1.65;
Δ = b2-4ac
Δ = -3.22-4·1·(-1.65)
Δ = 16.84
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3.2)-\sqrt{16.84}}{2*1}=\frac{3.2-\sqrt{16.84}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3.2)+\sqrt{16.84}}{2*1}=\frac{3.2+\sqrt{16.84}}{2}
$