4b(13b+9)=0

Solution for 4b(13b+9)=0 equation:

4b(13b+9)=0

We multiply parentheses

52b^2+36b=0

a = 52; b = 36; c = 0;
Δ = b2-4ac
Δ = 362-4·52·0
Δ = 1296
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1296}=36$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(36)-36}{2*52}=\frac{-72}{104}
=-9/13
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(36)+36}{2*52}=\frac{0}{104}
=0
$