8x^2=16x+64

Solution for 8x^2=16x+64 equation:

8x^2=16x+64

We move all terms to the left:

8x^2-(16x+64)=0

We get rid of parentheses

8x^2-16x-64=0

a = 8; b = -16; c = -64;
Δ = b2-4ac
Δ = -162-4·8·(-64)
Δ = 2304
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2304}=48$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-48}{2*8}=\frac{-32}{16}
=-2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+48}{2*8}=\frac{64}{16}
=4
$