5b^2-30=5b

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

5b^2-30=5b

We move all terms to the left:

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

a = 5; b = -5; c = -30;
Δ = b2-4ac
Δ = -52-4·5·(-30)
Δ = 625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{625}=25$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-25}{2*5}=\frac{-20}{10}
=-2
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+25}{2*5}=\frac{30}{10}
=3
$