(217+x)=1.25*(13-x)*(32.8-x)

Solution for (217+x)=1.25*(13-x)*(32.8-x) equation:

Simplifying
(217 + x) = 1.25(13 + -1x)(32.8 + -1x)

Remove parenthesis around (217 + x)
217 + x = 1.25(13 + -1x)(32.8 + -1x)

Multiply (13 + -1x) * (32.8 + -1x)
217 + x = 1.25(13(32.8 + -1x) + -1x * (32.8 + -1x))
217 + x = 1.25((32.8 * 13 + -1x * 13) + -1x * (32.8 + -1x))
217 + x = 1.25((426.4 + -13x) + -1x * (32.8 + -1x))
217 + x = 1.25(426.4 + -13x + (32.8 * -1x + -1x * -1x))
217 + x = 1.25(426.4 + -13x + (-32.8x + 1x2))

Combine like terms: -13x + -32.8x = -45.8x
217 + x = 1.25(426.4 + -45.8x + 1x2)
217 + x = (426.4 * 1.25 + -45.8x * 1.25 + 1x2 * 1.25)
217 + x = (533 + -57.25x + 1.25x2)

Solving
217 + x = 533 + -57.25x + 1.25x2

Solving for variable 'x'.

Reorder the terms:
217 + -533 + x + 57.25x + -1.25x2 = 533 + -57.25x + 1.25x2 + -533 + 57.25x + -1.25x2

Combine like terms: 217 + -533 = -316
-316 + x + 57.25x + -1.25x2 = 533 + -57.25x + 1.25x2 + -533 + 57.25x + -1.25x2

Combine like terms: x + 57.25x = 58.25x
-316 + 58.25x + -1.25x2 = 533 + -57.25x + 1.25x2 + -533 + 57.25x + -1.25x2

Reorder the terms:
-316 + 58.25x + -1.25x2 = 533 + -533 + -57.25x + 57.25x + 1.25x2 + -1.25x2

Combine like terms: 533 + -533 = 0
-316 + 58.25x + -1.25x2 = 0 + -57.25x + 57.25x + 1.25x2 + -1.25x2
-316 + 58.25x + -1.25x2 = -57.25x + 57.25x + 1.25x2 + -1.25x2

Combine like terms: -57.25x + 57.25x = 0.00
-316 + 58.25x + -1.25x2 = 0.00 + 1.25x2 + -1.25x2
-316 + 58.25x + -1.25x2 = 1.25x2 + -1.25x2

Combine like terms: 1.25x2 + -1.25x2 = 0.00
-316 + 58.25x + -1.25x2 = 0.00

Begin completing the square.  Divide all terms by
-1.25 the coefficient of the squared term: 

Divide each side by '-1.25'.
252.8 + -46.6x + x2 = 0

Move the constant term to the right:

Add '-252.8' to each side of the equation.
252.8 + -46.6x + -252.8 + x2 = 0 + -252.8

Reorder the terms:
252.8 + -252.8 + -46.6x + x2 = 0 + -252.8

Combine like terms: 252.8 + -252.8 = 0.0
0.0 + -46.6x + x2 = 0 + -252.8
-46.6x + x2 = 0 + -252.8

Combine like terms: 0 + -252.8 = -252.8
-46.6x + x2 = -252.8

The x term is -46.6x.  Take half its coefficient (-23.3).
Square it (542.89) and add it to both sides.

Add '542.89' to each side of the equation.
-46.6x + 542.89 + x2 = -252.8 + 542.89

Reorder the terms:
542.89 + -46.6x + x2 = -252.8 + 542.89

Combine like terms: -252.8 + 542.89 = 290.09
542.89 + -46.6x + x2 = 290.09

Factor a perfect square on the left side:
(x + -23.3)(x + -23.3) = 290.09

Calculate the square root of the right side: 17.032028652

Break this problem into two subproblems by setting 
(x + -23.3) equal to 17.032028652 and -17.032028652.

Subproblem 1
x + -23.3 = 17.032028652

Simplifying
x + -23.3 = 17.032028652

Reorder the terms:
-23.3 + x = 17.032028652

Solving
-23.3 + x = 17.032028652

Solving for variable 'x'.

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

Add '23.3' to each side of the equation.
-23.3 + 23.3 + x = 17.032028652 + 23.3

Combine like terms: -23.3 + 23.3 = 0.0
0.0 + x = 17.032028652 + 23.3
x = 17.032028652 + 23.3

Combine like terms: 17.032028652 + 23.3 = 40.332028652
x = 40.332028652

Simplifying
x = 40.332028652

Subproblem 2
x + -23.3 = -17.032028652

Simplifying
x + -23.3 = -17.032028652

Reorder the terms:
-23.3 + x = -17.032028652

Solving
-23.3 + x = -17.032028652

Solving for variable 'x'.

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

Add '23.3' to each side of the equation.
-23.3 + 23.3 + x = -17.032028652 + 23.3

Combine like terms: -23.3 + 23.3 = 0.0
0.0 + x = -17.032028652 + 23.3
x = -17.032028652 + 23.3

Combine like terms: -17.032028652 + 23.3 = 6.267971348
x = 6.267971348

Simplifying
x = 6.267971348

Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {40.332028652, 6.267971348}