7m^2-55m-8=0

Solution for 7m^2-55m-8=0 equation:

7m^2-55m-8=0

a = 7; b = -55; c = -8;
Δ = b2-4ac
Δ = -552-4·7·(-8)
Δ = 3249
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3249}=57$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-55)-57}{2*7}=\frac{-2}{14}
=-1/7
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-55)+57}{2*7}=\frac{112}{14}
=8
$