8x^2+68x=-84

Solution for 8x^2+68x=-84 equation:

8x^2+68x=-84

We move all terms to the left:

8x^2+68x-(-84)=0

We add all the numbers together, and all the variables

8x^2+68x+84=0

a = 8; b = 68; c = +84;
Δ = b2-4ac
Δ = 682-4·8·84
Δ = 1936
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1936}=44$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(68)-44}{2*8}=\frac{-112}{16}
=-7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(68)+44}{2*8}=\frac{-24}{16}
=-1+1/2
$