3b^2-40=-2b

Solution for 3b^2-40=-2b equation:

3b^2-40=-2b

We move all terms to the left:

3b^2-40-(-2b)=0

We get rid of parentheses

3b^2+2b-40=0

a = 3; b = 2; c = -40;
Δ = b2-4ac
Δ = 22-4·3·(-40)
Δ = 484
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{484}=22$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-22}{2*3}=\frac{-24}{6}
=-4
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+22}{2*3}=\frac{20}{6}
=3+1/3
$