z^2-2.2z^2+1.5z-0.35=0

Solution for z^2-2.2z^2+1.5z-0.35=0 equation:

z^2-2.2z^2+1.5z-0.35=0

We add all the numbers together, and all the variables

-1.2z^2+1.5z-0.35=0

a = -1.2; b = 1.5; c = -0.35;
Δ = b2-4ac
Δ = 1.52-4·(-1.2)·(-0.35)
Δ = 0.57
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1.5)-\sqrt{0.57}}{2*-1.2}=\frac{-1.5-\sqrt{0.57}}{-2.4}
$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1.5)+\sqrt{0.57}}{2*-1.2}=\frac{-1.5+\sqrt{0.57}}{-2.4}
$