72x=8x^2

Solution for 72x=8x^2 equation:

72x=8x^2

We move all terms to the left:

72x-(8x^2)=0

determiningTheFunctionDomain
-8x^2+72x=0

a = -8; b = 72; c = 0;
Δ = b2-4ac
Δ = 722-4·(-8)·0
Δ = 5184
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5184}=72$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(72)-72}{2*-8}=\frac{-144}{-16}
=+9
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(72)+72}{2*-8}=\frac{0}{-16}
=0
$