(X+7.3997)(x-10.5997)=0

Solution for (X+7.3997)(x-10.5997)=0 equation:

(X+7.3997)(X-10.5997)=0

We multiply parentheses ..

(+X^2-10.5997X+7.3997X-78.43460009)=0

We get rid of parentheses

X^2-10.5997X+7.3997X-78.43460009=0

We add all the numbers together, and all the variables

X^2-3.2X-78.43460009=0

a = 1; b = -3.2; c = -78.43460009;
Δ = b2-4ac
Δ = -3.22-4·1·(-78.43460009)
Δ = 323.97840036
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{-(-3.2)-\sqrt{323.97840036}}{2*1}=\frac{3.2-\sqrt{323.97840036}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3.2)+\sqrt{323.97840036}}{2*1}=\frac{3.2+\sqrt{323.97840036}}{2}
$