-z^2+3z=-2

Solution for -z^2+3z=-2 equation:

-z^2+3z=-2

We move all terms to the left:

-z^2+3z-(-2)=0

We add all the numbers together, and all the variables

-1z^2+3z+2=0

a = -1; b = 3; c = +2;
Δ = b2-4ac
Δ = 32-4·(-1)·2
Δ = 17
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{-(3)-\sqrt{17}}{2*-1}=\frac{-3-\sqrt{17}}{-2}
$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+\sqrt{17}}{2*-1}=\frac{-3+\sqrt{17}}{-2}
$