7b^2+14b=56

Solution for 7b^2+14b=56 equation:

7b^2+14b=56

We move all terms to the left:

7b^2+14b-(56)=0

a = 7; b = 14; c = -56;
Δ = b2-4ac
Δ = 142-4·7·(-56)
Δ = 1764
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1764}=42$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(14)-42}{2*7}=\frac{-56}{14}
=-4
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(14)+42}{2*7}=\frac{28}{14}
=2
$