50x^2-x-0.4=0

Solution for 50x^2-x-0.4=0 equation:

50x^2-x-0.4=0

We add all the numbers together, and all the variables

50x^2-1x-0.4=0

a = 50; b = -1; c = -0.4;
Δ = b2-4ac
Δ = -12-4·50·(-0.4)
Δ = 81
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{81}=9$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-9}{2*50}=\frac{-8}{100}
=-2/25
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+9}{2*50}=\frac{10}{100}
=1/10
$