8y2-14y-15=0

Solution for 8y2-14y-15=0 equation:

8y^2-14y-15=0

a = 8; b = -14; c = -15;
Δ = b2-4ac
Δ = -142-4·8·(-15)
Δ = 676
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{676}=26$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-26}{2*8}=\frac{-12}{16}
=-3/4
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+26}{2*8}=\frac{40}{16}
=2+1/2
$