8s2+14s=15

Solution for 8s2+14s=15 equation:

8s^2+14s=15

We move all terms to the left:

8s^2+14s-(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:
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

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