2b(10+3b)=64

Solution for 2b(10+3b)=64 equation:

2b(10+3b)=64

We move all terms to the left:

2b(10+3b)-(64)=0

We add all the numbers together, and all the variables

2b(3b+10)-64=0

We multiply parentheses

6b^2+20b-64=0

a = 6; b = 20; c = -64;
Δ = b2-4ac
Δ = 202-4·6·(-64)
Δ = 1936
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1936}=44$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-44}{2*6}=\frac{-64}{12}
=-5+1/3
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+44}{2*6}=\frac{24}{12}
=2
$