x2-15=7/8

Solution for x2-15=7/8 equation:

x2-15=7/8

We move all terms to the left:

x2-15-(7/8)=0

We add all the numbers together, and all the variables

x2-15-(+7/8)=0

We add all the numbers together, and all the variables

x^2-15-(+7/8)=0

We get rid of parentheses

x^2-15-7/8=0

We multiply all the terms by the denominator


x^2*8-7-15*8=0

We add all the numbers together, and all the variables

x^2*8-127=0

Wy multiply elements

8x^2-127=0

a = 8; b = 0; c = -127;
Δ = b2-4ac
Δ = 02-4·8·(-127)
Δ = 4064
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:

$\sqrt{\Delta}=\sqrt{4064}=\sqrt{16*254}=\sqrt{16}*\sqrt{254}=4\sqrt{254}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4\sqrt{254}}{2*8}=\frac{0-4\sqrt{254}}{16}
=-\frac{4\sqrt{254}}{16}
=-\frac{\sqrt{254}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4\sqrt{254}}{2*8}=\frac{0+4\sqrt{254}}{16}
=\frac{4\sqrt{254}}{16}
=\frac{\sqrt{254}}{4}
$