115=8x^2-10x

Solution for 115=8x^2-10x equation:

115=8x^2-10x

We move all terms to the left:

115-(8x^2-10x)=0

We get rid of parentheses

-8x^2+10x+115=0

a = -8; b = 10; c = +115;
Δ = b2-4ac
Δ = 102-4·(-8)·115
Δ = 3780
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:

$\sqrt{\Delta}=\sqrt{3780}=\sqrt{36*105}=\sqrt{36}*\sqrt{105}=6\sqrt{105}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-6\sqrt{105}}{2*-8}=\frac{-10-6\sqrt{105}}{-16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+6\sqrt{105}}{2*-8}=\frac{-10+6\sqrt{105}}{-16}
$