(x)=(x-2)(x+7)

Solution for (x)=(x-2)(x+7) equation:

(x)=(x-2)(x+7)

We move all terms to the left:

(x)-((x-2)(x+7))=0

We multiply parentheses ..

-((+x^2+7x-2x-14))+x=0


We calculate terms in parentheses: -((+x^2+7x-2x-14)), so:

(+x^2+7x-2x-14)

We get rid of parentheses

x^2+7x-2x-14

We add all the numbers together, and all the variables

x^2+5x-14

Back to the equation:

-(x^2+5x-14)


We add all the numbers together, and all the variables

x-(x^2+5x-14)=0

We get rid of parentheses

-x^2+x-5x+14=0

We add all the numbers together, and all the variables

-1x^2-4x+14=0

a = -1; b = -4; c = +14;
Δ = b2-4ac
Δ = -42-4·(-1)·14
Δ = 72
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:

$\sqrt{\Delta}=\sqrt{72}=\sqrt{36*2}=\sqrt{36}*\sqrt{2}=6\sqrt{2}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4)-6\sqrt{2}}{2*-1}=\frac{4-6\sqrt{2}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+6\sqrt{2}}{2*-1}=\frac{4+6\sqrt{2}}{-2}
$