3(2x^2+8)=78

Solution for 3(2x^2+8)=78 equation:

3(2x^2+8)=78

We move all terms to the left:

3(2x^2+8)-(78)=0

We multiply parentheses

6x^2+24-78=0

We add all the numbers together, and all the variables

6x^2-54=0

a = 6; b = 0; c = -54;
Δ = b2-4ac
Δ = 02-4·6·(-54)
Δ = 1296
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1296}=36$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-36}{2*6}=\frac{-36}{12}
=-3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+36}{2*6}=\frac{36}{12}
=3
$