11y2-15-13=0

Solution for 11y2-15-13=0 equation:

11y^2-15-13=0

We add all the numbers together, and all the variables

11y^2-28=0

a = 11; b = 0; c = -28;
Δ = b2-4ac
Δ = 02-4·11·(-28)
Δ = 1232
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1232}=\sqrt{16*77}=\sqrt{16}*\sqrt{77}=4\sqrt{77}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4\sqrt{77}}{2*11}=\frac{0-4\sqrt{77}}{22}
=-\frac{4\sqrt{77}}{22}
=-\frac{2\sqrt{77}}{11}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4\sqrt{77}}{2*11}=\frac{0+4\sqrt{77}}{22}
=\frac{4\sqrt{77}}{22}
=\frac{2\sqrt{77}}{11}
$