140=(x+4)(x+9)

Solution for 140=(x+4)(x+9) equation:

140=(x+4)(x+9)

We move all terms to the left:

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

We multiply parentheses ..

-((+x^2+9x+4x+36))+140=0


We calculate terms in parentheses: -((+x^2+9x+4x+36)), so:

(+x^2+9x+4x+36)

We get rid of parentheses

x^2+9x+4x+36

We add all the numbers together, and all the variables

x^2+13x+36

Back to the equation:

-(x^2+13x+36)


We get rid of parentheses

-x^2-13x-36+140=0

We add all the numbers together, and all the variables

-1x^2-13x+104=0

a = -1; b = -13; c = +104;
Δ = b2-4ac
Δ = -132-4·(-1)·104
Δ = 585
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:

$\sqrt{\Delta}=\sqrt{585}=\sqrt{9*65}=\sqrt{9}*\sqrt{65}=3\sqrt{65}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-13)-3\sqrt{65}}{2*-1}=\frac{13-3\sqrt{65}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-13)+3\sqrt{65}}{2*-1}=\frac{13+3\sqrt{65}}{-2}
$