28x^2+200x+28=0

Solution for 28x^2+200x+28=0 equation:

28x^2+200x+28=0

a = 28; b = 200; c = +28;
Δ = b2-4ac
Δ = 2002-4·28·28
Δ = 36864
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36864}=192$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(200)-192}{2*28}=\frac{-392}{56}
=-7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(200)+192}{2*28}=\frac{-8}{56}
=-1/7
$