675=(x+6)(x-4)

Solution for 675=(x+6)(x-4) equation:

675=(x+6)(x-4)

We move all terms to the left:

675-((x+6)(x-4))=0

We multiply parentheses ..

-((+x^2-4x+6x-24))+675=0


We calculate terms in parentheses: -((+x^2-4x+6x-24)), so:

(+x^2-4x+6x-24)

We get rid of parentheses

x^2-4x+6x-24

We add all the numbers together, and all the variables

x^2+2x-24

Back to the equation:

-(x^2+2x-24)


We get rid of parentheses

-x^2-2x+24+675=0

We add all the numbers together, and all the variables

-1x^2-2x+699=0

a = -1; b = -2; c = +699;
Δ = b2-4ac
Δ = -22-4·(-1)·699
Δ = 2800
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{2800}=\sqrt{400*7}=\sqrt{400}*\sqrt{7}=20\sqrt{7}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-20\sqrt{7}}{2*-1}=\frac{2-20\sqrt{7}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+20\sqrt{7}}{2*-1}=\frac{2+20\sqrt{7}}{-2}
$