(x=9)(x-4)(x+7)

Solution for (x=9)(x-4)(x+7) equation:

(x=9)(x-4)(x+7)

We move all terms to the left:

(x-(9)(x-4)(x+7))=0

We multiply parentheses ..

(x-9(+x^2+7x-4x-28))=0


We calculate terms in parentheses: +(x-9(+x^2+7x-4x-28)), so:

x-9(+x^2+7x-4x-28)

determiningTheFunctionDomain
-9(+x^2+7x-4x-28)+x

We multiply parentheses

-9x^2-63x+36x+x+252

We add all the numbers together, and all the variables

-9x^2-26x+252

Back to the equation:

+(-9x^2-26x+252)


We get rid of parentheses

-9x^2-26x+252=0

a = -9; b = -26; c = +252;
Δ = b2-4ac
Δ = -262-4·(-9)·252
Δ = 9748
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:

$\sqrt{\Delta}=\sqrt{9748}=\sqrt{4*2437}=\sqrt{4}*\sqrt{2437}=2\sqrt{2437}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-26)-2\sqrt{2437}}{2*-9}=\frac{26-2\sqrt{2437}}{-18}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-26)+2\sqrt{2437}}{2*-9}=\frac{26+2\sqrt{2437}}{-18}
$