11x^2-2x-86=2x^2-2x-5

Solution for 11x^2-2x-86=2x^2-2x-5 equation:

11x^2-2x-86=2x^2-2x-5

We move all terms to the left:

11x^2-2x-86-(2x^2-2x-5)=0

We get rid of parentheses

11x^2-2x^2-2x+2x+5-86=0

We add all the numbers together, and all the variables

9x^2-81=0

a = 9; b = 0; c = -81;
Δ = b2-4ac
Δ = 02-4·9·(-81)
Δ = 2916
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2916}=54$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-54}{2*9}=\frac{-54}{18}
=-3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+54}{2*9}=\frac{54}{18}
=3
$