5*x^2+74*x+128=0

Solution for 5*x^2+74*x+128=0 equation:

5x^2+74x+128=0

a = 5; b = 74; c = +128;
Δ = b2-4ac
Δ = 742-4·5·128
Δ = 2916
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2916}=54$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(74)-54}{2*5}=\frac{-128}{10}
=-12+4/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(74)+54}{2*5}=\frac{-20}{10}
=-2
$