(X-0.6)(x+0.9)=0

Solution for (X-0.6)(x+0.9)=0 equation:

(X-0.6)(X+0.9)=0

We multiply parentheses ..

(+X^2+0.9X-0.6X-0.54)=0

We get rid of parentheses

X^2+0.9X-0.6X-0.54=0

We add all the numbers together, and all the variables

X^2+0.3X-0.54=0

a = 1; b = 0.3; c = -0.54;
Δ = b2-4ac
Δ = 0.32-4·1·(-0.54)
Δ = 2.25
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{-(0.3)-\sqrt{2.25}}{2*1}=\frac{-0.3-\sqrt{2.25}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.3)+\sqrt{2.25}}{2*1}=\frac{-0.3+\sqrt{2.25}}{2}
$