4+9z+z2=0

Solution for 4+9z+z2=0 equation:

4+9z+z2=0

We add all the numbers together, and all the variables

z^2+9z+4=0

a = 1; b = 9; c = +4;
Δ = b2-4ac
Δ = 92-4·1·4
Δ = 65
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{-(9)-\sqrt{65}}{2*1}=\frac{-9-\sqrt{65}}{2}
$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+\sqrt{65}}{2*1}=\frac{-9+\sqrt{65}}{2}
$