56=8(x^2)

Solution for 56=8(x^2) equation:

56=8(x^2)

We move all terms to the left:

56-(8(x^2))=0

determiningTheFunctionDomain
-8x^2+56=0

a = -8; b = 0; c = +56;
Δ = b2-4ac
Δ = 02-4·(-8)·56
Δ = 1792
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1792}=\sqrt{256*7}=\sqrt{256}*\sqrt{7}=16\sqrt{7}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-16\sqrt{7}}{2*-8}=\frac{0-16\sqrt{7}}{-16}
=-\frac{16\sqrt{7}}{-16}
=-\frac{\sqrt{7}}{-1}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+16\sqrt{7}}{2*-8}=\frac{0+16\sqrt{7}}{-16}
=\frac{16\sqrt{7}}{-16}
=\frac{\sqrt{7}}{-1}
$