(0.4b-0.08)(0.04b+1)=0

Solution for (0.4b-0.08)(0.04b+1)=0 equation:

(0.4b-0.08)(0.04b+1)=0

We multiply parentheses ..

(+0b^2+0b-0b-0.08)=0

We get rid of parentheses

0b^2+0b-0b-0.08=0

We add all the numbers together, and all the variables

b^2-0.08=0

a = 1; b = 0; c = -0.08;
Δ = b2-4ac
Δ = 02-4·1·(-0.08)
Δ = 0.32
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{-(0)-\sqrt{0.32}}{2*1}=\frac{0-\sqrt{0.32}}{2}
=-\frac{\sqrt{}}{2}
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{0.32}}{2*1}=\frac{0+\sqrt{0.32}}{2}
=\frac{\sqrt{}}{2}
$