(x+4,25)(x-7,75)=0

Solution for (x+4,25)(x-7,75)=0 equation:

(x+4.25)(x-7.75)=0

We multiply parentheses ..

(+x^2-7.75x+4.25x-32.9375)=0

We get rid of parentheses

x^2-7.75x+4.25x-32.9375=0

We add all the numbers together, and all the variables

x^2-3.5x-32.9375=0

a = 1; b = -3.5; c = -32.9375;
Δ = b2-4ac
Δ = -3.52-4·1·(-32.9375)
Δ = 144
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{144}=12$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3.5)-12}{2*1}=\frac{-8.5}{2}
=-4+0.5/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3.5)+12}{2*1}=\frac{15.5}{2}
=7+1/1.3333333333333
$