3b(5-4b)=0

Solution for 3b(5-4b)=0 equation:

3b(5-4b)=0

We add all the numbers together, and all the variables

3b(-4b+5)=0

We multiply parentheses

-12b^2+15b=0

a = -12; b = 15; c = 0;
Δ = b2-4ac
Δ = 152-4·(-12)·0
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-15}{2*-12}=\frac{-30}{-24}
=1+1/4
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+15}{2*-12}=\frac{0}{-24}
=0
$