b^2-5b-2b^2-4b+30=b^2+2b

Solution for b^2-5b-2b^2-4b+30=b^2+2b equation:

b^2-5b-2b^2-4b+30=b^2+2b

We move all terms to the left:

b^2-5b-2b^2-4b+30-(b^2+2b)=0

We add all the numbers together, and all the variables

-1b^2-9b-(b^2+2b)+30=0

We get rid of parentheses

-1b^2-b^2-9b-2b+30=0

We add all the numbers together, and all the variables

-2b^2-11b+30=0

a = -2; b = -11; c = +30;
Δ = b2-4ac
Δ = -112-4·(-2)·30
Δ = 361
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{361}=19$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-11)-19}{2*-2}=\frac{-8}{-4}
=+2
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-11)+19}{2*-2}=\frac{30}{-4}
=-7+1/2
$