5y^2-26y-15=0

Solution for 5y^2-26y-15=0 equation:

5y^2-26y-15=0

a = 5; b = -26; c = -15;
Δ = b2-4ac
Δ = -262-4·5·(-15)
Δ = 976
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:

$\sqrt{\Delta}=\sqrt{976}=\sqrt{16*61}=\sqrt{16}*\sqrt{61}=4\sqrt{61}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-26)-4\sqrt{61}}{2*5}=\frac{26-4\sqrt{61}}{10}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-26)+4\sqrt{61}}{2*5}=\frac{26+4\sqrt{61}}{10}
$