4x-36=4x(x-9)

Solution for 4x-36=4x(x-9) equation:

4x-36=4x(x-9)

We move all terms to the left:

4x-36-(4x(x-9))=0


We calculate terms in parentheses: -(4x(x-9)), so:

4x(x-9)

We multiply parentheses

4x^2-36x

Back to the equation:

-(4x^2-36x)


We get rid of parentheses

-4x^2+4x+36x-36=0

We add all the numbers together, and all the variables

-4x^2+40x-36=0

a = -4; b = 40; c = -36;
Δ = b2-4ac
Δ = 402-4·(-4)·(-36)
Δ = 1024
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1024}=32$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(40)-32}{2*-4}=\frac{-72}{-8}
=+9
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(40)+32}{2*-4}=\frac{-8}{-8}
=1
$