8x^2+56x+196=676

Solution for 8x^2+56x+196=676 equation:

8x^2+56x+196=676

We move all terms to the left:

8x^2+56x+196-(676)=0

We add all the numbers together, and all the variables

8x^2+56x-480=0

a = 8; b = 56; c = -480;
Δ = b2-4ac
Δ = 562-4·8·(-480)
Δ = 18496
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{18496}=136$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(56)-136}{2*8}=\frac{-192}{16}
=-12
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(56)+136}{2*8}=\frac{80}{16}
=5
$