3x^2+28x+55=0

Solution for 3x^2+28x+55=0 equation:

3x^2+28x+55=0

a = 3; b = 28; c = +55;
Δ = b2-4ac
Δ = 282-4·3·55
Δ = 124
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{124}=\sqrt{4*31}=\sqrt{4}*\sqrt{31}=2\sqrt{31}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(28)-2\sqrt{31}}{2*3}=\frac{-28-2\sqrt{31}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(28)+2\sqrt{31}}{2*3}=\frac{-28+2\sqrt{31}}{6}
$