(1.2-x)(1-x)=0

Solution for (1.2-x)(1-x)=0 equation:

Simplifying
(1.2 + -1x)(1 + -1x) = 0

Multiply (1.2 + -1x) * (1 + -1x)
(1.2(1 + -1x) + -1x * (1 + -1x)) = 0
((1 * 1.2 + -1x * 1.2) + -1x * (1 + -1x)) = 0
((1.2 + -1.2x) + -1x * (1 + -1x)) = 0
(1.2 + -1.2x + (1 * -1x + -1x * -1x)) = 0
(1.2 + -1.2x + (-1x + 1x2)) = 0

Combine like terms: -1.2x + -1x = -2.2x
(1.2 + -2.2x + 1x2) = 0

Solving
1.2 + -2.2x + 1x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '-1.2' to each side of the equation.
1.2 + -2.2x + -1.2 + x2 = 0 + -1.2

Reorder the terms:
1.2 + -1.2 + -2.2x + x2 = 0 + -1.2

Combine like terms: 1.2 + -1.2 = 0.0
0.0 + -2.2x + x2 = 0 + -1.2
-2.2x + x2 = 0 + -1.2

Combine like terms: 0 + -1.2 = -1.2
-2.2x + x2 = -1.2

The x term is -2.2x.  Take half its coefficient (-1.1).
Square it (1.21) and add it to both sides.

Add '1.21' to each side of the equation.
-2.2x + 1.21 + x2 = -1.2 + 1.21

Reorder the terms:
1.21 + -2.2x + x2 = -1.2 + 1.21

Combine like terms: -1.2 + 1.21 = 0.01
1.21 + -2.2x + x2 = 0.01

Factor a perfect square on the left side:
(x + -1.1)(x + -1.1) = 0.01

Calculate the square root of the right side: 0.1

Break this problem into two subproblems by setting 
(x + -1.1) equal to 0.1 and -0.1.

Subproblem 1
x + -1.1 = 0.1

Simplifying
x + -1.1 = 0.1

Reorder the terms:
-1.1 + x = 0.1

Solving
-1.1 + x = 0.1

Solving for variable 'x'.

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

Add '1.1' to each side of the equation.
-1.1 + 1.1 + x = 0.1 + 1.1

Combine like terms: -1.1 + 1.1 = 0.0
0.0 + x = 0.1 + 1.1
x = 0.1 + 1.1

Combine like terms: 0.1 + 1.1 = 1.2
x = 1.2

Simplifying
x = 1.2

Subproblem 2
x + -1.1 = -0.1

Simplifying
x + -1.1 = -0.1

Reorder the terms:
-1.1 + x = -0.1

Solving
-1.1 + x = -0.1

Solving for variable 'x'.

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

Add '1.1' to each side of the equation.
-1.1 + 1.1 + x = -0.1 + 1.1

Combine like terms: -1.1 + 1.1 = 0.0
0.0 + x = -0.1 + 1.1
x = -0.1 + 1.1

Combine like terms: -0.1 + 1.1 = 1
x = 1

Simplifying
x = 1

Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {1.2, 1}