(5-x)(x+7,3)=0

Solution for (5-x)(x+7,3)=0 equation:

(5-x)(x+7.3)=0

We add all the numbers together, and all the variables

(-1x+5)(x+7.3)=0

We multiply parentheses ..

(-1x^2-7.3x+5x+36.5)=0

We get rid of parentheses

-1x^2-7.3x+5x+36.5=0

We add all the numbers together, and all the variables

-1x^2-2.3x+36.5=0

a = -1; b = -2.3; c = +36.5;
Δ = b2-4ac
Δ = -2.32-4·(-1)·36.5
Δ = 151.29
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{-(-2.3)-\sqrt{151.29}}{2*-1}=\frac{2.3-\sqrt{151.29}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2.3)+\sqrt{151.29}}{2*-1}=\frac{2.3+\sqrt{151.29}}{-2}
$