12=4(b-2)b=

Solution for 12=4(b-2)b= equation:

12=4(b-2)b=

We move all terms to the left:

12-(4(b-2)b)=0


We calculate terms in parentheses: -(4(b-2)b), so:

4(b-2)b

We multiply parentheses

4b^2-8b

Back to the equation:

-(4b^2-8b)


We get rid of parentheses

-4b^2+8b+12=0

a = -4; b = 8; c = +12;
Δ = b2-4ac
Δ = 82-4·(-4)·12
Δ = 256
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{256}=16$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-16}{2*-4}=\frac{-24}{-8}
=+3
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+16}{2*-4}=\frac{8}{-8}
=-1
$