2x^2+26x=-84

Solution for 2x^2+26x=-84 equation:

2x^2+26x=-84

We move all terms to the left:

2x^2+26x-(-84)=0

We add all the numbers together, and all the variables

2x^2+26x+84=0

a = 2; b = 26; c = +84;
Δ = b2-4ac
Δ = 262-4·2·84
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4}=2$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(26)-2}{2*2}=\frac{-28}{4}
=-7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(26)+2}{2*2}=\frac{-24}{4}
=-6
$