0.02W^2-0.3W=20

Solution for 0.02W^2-0.3W=20 equation:

Simplifying
0.02W2 + -0.3W = 20

Reorder the terms:
-0.3W + 0.02W2 = 20

Solving
-0.3W + 0.02W2 = 20

Solving for variable 'W'.

Reorder the terms:
-20 + -0.3W + 0.02W2 = 20 + -20

Combine like terms: 20 + -20 = 0
-20 + -0.3W + 0.02W2 = 0

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

Divide each side by '0.02'.
-1000 + -15W + W2 = 0

Move the constant term to the right:

Add '1000' to each side of the equation.
-1000 + -15W + 1000 + W2 = 0 + 1000

Reorder the terms:
-1000 + 1000 + -15W + W2 = 0 + 1000

Combine like terms: -1000 + 1000 = 0
0 + -15W + W2 = 0 + 1000
-15W + W2 = 0 + 1000

Combine like terms: 0 + 1000 = 1000
-15W + W2 = 1000

The W term is -15W.  Take half its coefficient (-7.5).
Square it (56.25) and add it to both sides.

Add '56.25' to each side of the equation.
-15W + 56.25 + W2 = 1000 + 56.25

Reorder the terms:
56.25 + -15W + W2 = 1000 + 56.25

Combine like terms: 1000 + 56.25 = 1056.25
56.25 + -15W + W2 = 1056.25

Factor a perfect square on the left side:
(W + -7.5)(W + -7.5) = 1056.25

Calculate the square root of the right side: 32.5

Break this problem into two subproblems by setting 
(W + -7.5) equal to 32.5 and -32.5.

Subproblem 1
W + -7.5 = 32.5

Simplifying
W + -7.5 = 32.5

Reorder the terms:
-7.5 + W = 32.5

Solving
-7.5 + W = 32.5

Solving for variable 'W'.

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

Add '7.5' to each side of the equation.
-7.5 + 7.5 + W = 32.5 + 7.5

Combine like terms: -7.5 + 7.5 = 0.0
0.0 + W = 32.5 + 7.5
W = 32.5 + 7.5

Combine like terms: 32.5 + 7.5 = 40
W = 40

Simplifying
W = 40

Subproblem 2
W + -7.5 = -32.5

Simplifying
W + -7.5 = -32.5

Reorder the terms:
-7.5 + W = -32.5

Solving
-7.5 + W = -32.5

Solving for variable 'W'.

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

Add '7.5' to each side of the equation.
-7.5 + 7.5 + W = -32.5 + 7.5

Combine like terms: -7.5 + 7.5 = 0.0
0.0 + W = -32.5 + 7.5
W = -32.5 + 7.5

Combine like terms: -32.5 + 7.5 = -25
W = -25

Simplifying
W = -25

Solution
The solution to the problem is based on the solutions
from the subproblems.
W = {40, -25}