15x^2+(-56)=88+6x^2

Solution for 15x^2+(-56)=88+6x^2 equation:

15x^2+(-56)=88+6x^2

We move all terms to the left:

15x^2+(-56)-(88+6x^2)=0

We add all the numbers together, and all the variables

15x^2-(88+6x^2)-56=0

We get rid of parentheses

15x^2-6x^2-88-56=0

We add all the numbers together, and all the variables

9x^2-144=0

a = 9; b = 0; c = -144;
Δ = b2-4ac
Δ = 02-4·9·(-144)
Δ = 5184
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5184}=72$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-72}{2*9}=\frac{-72}{18}
=-4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+72}{2*9}=\frac{72}{18}
=4
$