40m^2-39m-40=0

Solution for 40m^2-39m-40=0 equation:

40m^2-39m-40=0

a = 40; b = -39; c = -40;
Δ = b2-4ac
Δ = -392-4·40·(-40)
Δ = 7921
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7921}=89$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-39)-89}{2*40}=\frac{-50}{80}
=-5/8
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-39)+89}{2*40}=\frac{128}{80}
=1+3/5
$