9x^2-0.4x-0.04=0

Solution for 9x^2-0.4x-0.04=0 equation:

9x^2-0.4x-0.04=0

a = 9; b = -0.4; c = -0.04;
Δ = b2-4ac
Δ = -0.42-4·9·(-0.04)
Δ = 1.6
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-0.4)-\sqrt{1.6}}{2*9}=\frac{0.4-\sqrt{1.6}}{18}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.4)+\sqrt{1.6}}{2*9}=\frac{0.4+\sqrt{1.6}}{18}
$