3b2-b=15

Solution for 3b2-b=15 equation:

3b^2-b=15

We move all terms to the left:

3b^2-b-(15)=0

We add all the numbers together, and all the variables

3b^2-1b-15=0

a = 3; b = -1; c = -15;
Δ = b2-4ac
Δ = -12-4·3·(-15)
Δ = 181
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-\sqrt{181}}{2*3}=\frac{1-\sqrt{181}}{6}
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{181}}{2*3}=\frac{1+\sqrt{181}}{6}
$