0=x^2+28x+75

Solution for 0=x^2+28x+75 equation:

0=x^2+28x+75

We move all terms to the left:

0-(x^2+28x+75)=0

We add all the numbers together, and all the variables

-(x^2+28x+75)=0

We get rid of parentheses

-x^2-28x-75=0

We add all the numbers together, and all the variables

-1x^2-28x-75=0

a = -1; b = -28; c = -75;
Δ = b2-4ac
Δ = -282-4·(-1)·(-75)
Δ = 484
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{484}=22$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-28)-22}{2*-1}=\frac{6}{-2}
=-3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-28)+22}{2*-1}=\frac{50}{-2}
=-25
$