2x^2+21x+25=-2

Solution for 2x^2+21x+25=-2 equation:

2x^2+21x+25=-2

We move all terms to the left:

2x^2+21x+25-(-2)=0

We add all the numbers together, and all the variables

2x^2+21x+27=0

a = 2; b = 21; c = +27;
Δ = b2-4ac
Δ = 212-4·2·27
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(21)-15}{2*2}=\frac{-36}{4}
=-9
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(21)+15}{2*2}=\frac{-6}{4}
=-1+1/2
$