-b^2-b+30=0

Solution for -b^2-b+30=0 equation:

-b^2-b+30=0

We add all the numbers together, and all the variables

-1b^2-1b+30=0

a = -1; b = -1; c = +30;
Δ = b2-4ac
Δ = -12-4·(-1)·30
Δ = 121
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{121}=11$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-11}{2*-1}=\frac{-10}{-2}
=+5
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+11}{2*-1}=\frac{12}{-2}
=-6
$