x2+9x+12=0

Solution for x2+9x+12=0 equation:

x2+9x+12=0

We add all the numbers together, and all the variables

x^2+9x+12=0

a = 1; b = 9; c = +12;
Δ = b2-4ac
Δ = 92-4·1·12
Δ = 33
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{-(9)-\sqrt{33}}{2*1}=\frac{-9-\sqrt{33}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+\sqrt{33}}{2*1}=\frac{-9+\sqrt{33}}{2}
$