7x^2-4=104

Solution for 7x^2-4=104 equation:

7x^2-4=104

We move all terms to the left:

7x^2-4-(104)=0

We add all the numbers together, and all the variables

7x^2-108=0

a = 7; b = 0; c = -108;
Δ = b2-4ac
Δ = 02-4·7·(-108)
Δ = 3024
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:

$\sqrt{\Delta}=\sqrt{3024}=\sqrt{144*21}=\sqrt{144}*\sqrt{21}=12\sqrt{21}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-12\sqrt{21}}{2*7}=\frac{0-12\sqrt{21}}{14}
=-\frac{12\sqrt{21}}{14}
=-\frac{6\sqrt{21}}{7}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+12\sqrt{21}}{2*7}=\frac{0+12\sqrt{21}}{14}
=\frac{12\sqrt{21}}{14}
=\frac{6\sqrt{21}}{7}
$