11r2-r-2=0

Solution for 11r2-r-2=0 equation:

11r^2-r-2=0

We add all the numbers together, and all the variables

11r^2-1r-2=0

a = 11; b = -1; c = -2;
Δ = b2-4ac
Δ = -12-4·11·(-2)
Δ = 89
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-\sqrt{89}}{2*11}=\frac{1-\sqrt{89}}{22}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{89}}{2*11}=\frac{1+\sqrt{89}}{22}
$