-56x^2-15x-1=0

Solution for -56x^2-15x-1=0 equation:

-56x^2-15x-1=0

a = -56; b = -15; c = -1;
Δ = b2-4ac
Δ = -152-4·(-56)·(-1)
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-1}{2*-56}=\frac{14}{-112}
=-1/8
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+1}{2*-56}=\frac{16}{-112}
=-1/7
$