28x^2+116x-120=0

Solution for 28x^2+116x-120=0 equation:

28x^2+116x-120=0

a = 28; b = 116; c = -120;
Δ = b2-4ac
Δ = 1162-4·28·(-120)
Δ = 26896
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{26896}=164$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(116)-164}{2*28}=\frac{-280}{56}
=-5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(116)+164}{2*28}=\frac{48}{56}
=6/7
$