X=9(y+13)(y-8)

Solution for X=9(y+13)(y-8) equation:

X=9(X+13)(X-8)

We move all terms to the left:

X-(9(X+13)(X-8))=0

We multiply parentheses ..

-(9(+X^2-8X+13X-104))+X=0


We calculate terms in parentheses: -(9(+X^2-8X+13X-104)), so:

9(+X^2-8X+13X-104)

We multiply parentheses

9X^2-72X+117X-936

We add all the numbers together, and all the variables

9X^2+45X-936

Back to the equation:

-(9X^2+45X-936)


We add all the numbers together, and all the variables

X-(9X^2+45X-936)=0

We get rid of parentheses

-9X^2+X-45X+936=0

We add all the numbers together, and all the variables

-9X^2-44X+936=0

a = -9; b = -44; c = +936;
Δ = b2-4ac
Δ = -442-4·(-9)·936
Δ = 35632
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:

$\sqrt{\Delta}=\sqrt{35632}=\sqrt{16*2227}=\sqrt{16}*\sqrt{2227}=4\sqrt{2227}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-44)-4\sqrt{2227}}{2*-9}=\frac{44-4\sqrt{2227}}{-18}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-44)+4\sqrt{2227}}{2*-9}=\frac{44+4\sqrt{2227}}{-18}
$