8x^2-14=15

Solution for 8x^2-14=15 equation:

8x^2-14=15

We move all terms to the left:

8x^2-14-(15)=0

We add all the numbers together, and all the variables

8x^2-29=0

a = 8; b = 0; c = -29;
Δ = b2-4ac
Δ = 02-4·8·(-29)
Δ = 928
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:

$\sqrt{\Delta}=\sqrt{928}=\sqrt{16*58}=\sqrt{16}*\sqrt{58}=4\sqrt{58}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4\sqrt{58}}{2*8}=\frac{0-4\sqrt{58}}{16}
=-\frac{4\sqrt{58}}{16}
=-\frac{\sqrt{58}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4\sqrt{58}}{2*8}=\frac{0+4\sqrt{58}}{16}
=\frac{4\sqrt{58}}{16}
=\frac{\sqrt{58}}{4}
$