56m^2-15m-56=0

Solution for 56m^2-15m-56=0 equation:

56m^2-15m-56=0

a = 56; b = -15; c = -56;
Δ = b2-4ac
Δ = -152-4·56·(-56)
Δ = 12769
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{12769}=113$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-113}{2*56}=\frac{-98}{112}
=-7/8
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+113}{2*56}=\frac{128}{112}
=1+1/7
$