(x-4)-(x^2-4x)=0

Solution for (x-4)-(x^2-4x)=0 equation:

Simplifying
(x + -4) + -1(x2 + -4x) = 0

Reorder the terms:
(-4 + x) + -1(x2 + -4x) = 0

Remove parenthesis around (-4 + x)
-4 + x + -1(x2 + -4x) = 0

Reorder the terms:
-4 + x + -1(-4x + x2) = 0
-4 + x + (-4x * -1 + x2 * -1) = 0
-4 + x + (4x + -1x2) = 0

Combine like terms: x + 4x = 5x
-4 + 5x + -1x2 = 0

Solving
-4 + 5x + -1x2 = 0

Solving for variable 'x'.

Factor a trinomial.
(-4 + x)(1 + -1x) = 0

Subproblem 1
Set the factor '(-4 + x)' equal to zero and attempt to solve:

Simplifying
-4 + x = 0

Solving
-4 + x = 0

Move all terms containing x to the left, all other terms to the right.

Add '4' to each side of the equation.
-4 + 4 + x = 0 + 4

Combine like terms: -4 + 4 = 0
0 + x = 0 + 4
x = 0 + 4

Combine like terms: 0 + 4 = 4
x = 4

Simplifying
x = 4
Subproblem 2
Set the factor '(1 + -1x)' equal to zero and attempt to solve:

Simplifying
1 + -1x = 0

Solving
1 + -1x = 0

Move all terms containing x to the left, all other terms to the right.

Add '-1' to each side of the equation.
1 + -1 + -1x = 0 + -1

Combine like terms: 1 + -1 = 0
0 + -1x = 0 + -1
-1x = 0 + -1

Combine like terms: 0 + -1 = -1
-1x = -1

Divide each side by '-1'.
x = 1

Simplifying
x = 1
Solution
x = {4, 1}