8x2/2=81

Solution for 8x2/2=81 equation:

8x^2/2=81

We move all terms to the left:

8x^2/2-(81)=0

We multiply all the terms by the denominator


8x^2-81*2=0

We add all the numbers together, and all the variables

8x^2-162=0

a = 8; b = 0; c = -162;
Δ = b2-4ac
Δ = 02-4·8·(-162)
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{-(0)-72}{2*8}=\frac{-72}{16}
=-4+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+72}{2*8}=\frac{72}{16}
=4+1/2
$