-27b^2+27b+84=0

Solution for -27b^2+27b+84=0 equation:

-27b^2+27b+84=0

a = -27; b = 27; c = +84;
Δ = b2-4ac
Δ = 272-4·(-27)·84
Δ = 9801
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9801}=99$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(27)-99}{2*-27}=\frac{-126}{-54}
=2+1/3
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(27)+99}{2*-27}=\frac{72}{-54}
=-1+1/3
$