-39=5(y-7)7y

Solution for -39=5(y-7)7y equation:

Simplifying
-39 = 5(y + -7) * 7y

Reorder the terms:
-39 = 5(-7 + y) * 7y

Reorder the terms for easier multiplication:
-39 = 5 * 7y(-7 + y)

Multiply 5 * 7
-39 = 35y(-7 + y)
-39 = (-7 * 35y + y * 35y)
-39 = (-245y + 35y2)

Solving
-39 = -245y + 35y2

Solving for variable 'y'.

Reorder the terms:
-39 + 245y + -35y2 = -245y + 245y + 35y2 + -35y2

Combine like terms: -245y + 245y = 0
-39 + 245y + -35y2 = 0 + 35y2 + -35y2
-39 + 245y + -35y2 = 35y2 + -35y2

Combine like terms: 35y2 + -35y2 = 0
-39 + 245y + -35y2 = 0

Begin completing the square.  Divide all terms by
-35 the coefficient of the squared term: 

Divide each side by '-35'.
1.114285714 + -7y + y2 = 0

Move the constant term to the right:

Add '-1.114285714' to each side of the equation.
1.114285714 + -7y + -1.114285714 + y2 = 0 + -1.114285714

Reorder the terms:
1.114285714 + -1.114285714 + -7y + y2 = 0 + -1.114285714

Combine like terms: 1.114285714 + -1.114285714 = 0.000000000
0.000000000 + -7y + y2 = 0 + -1.114285714
-7y + y2 = 0 + -1.114285714

Combine like terms: 0 + -1.114285714 = -1.114285714
-7y + y2 = -1.114285714

The y term is -7y.  Take half its coefficient (-3.5).
Square it (12.25) and add it to both sides.

Add '12.25' to each side of the equation.
-7y + 12.25 + y2 = -1.114285714 + 12.25

Reorder the terms:
12.25 + -7y + y2 = -1.114285714 + 12.25

Combine like terms: -1.114285714 + 12.25 = 11.135714286
12.25 + -7y + y2 = 11.135714286

Factor a perfect square on the left side:
(y + -3.5)(y + -3.5) = 11.135714286

Calculate the square root of the right side: 3.337021769

Break this problem into two subproblems by setting 
(y + -3.5) equal to 3.337021769 and -3.337021769.

Subproblem 1
y + -3.5 = 3.337021769

Simplifying
y + -3.5 = 3.337021769

Reorder the terms:
-3.5 + y = 3.337021769

Solving
-3.5 + y = 3.337021769

Solving for variable 'y'.

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

Add '3.5' to each side of the equation.
-3.5 + 3.5 + y = 3.337021769 + 3.5

Combine like terms: -3.5 + 3.5 = 0.0
0.0 + y = 3.337021769 + 3.5
y = 3.337021769 + 3.5

Combine like terms: 3.337021769 + 3.5 = 6.837021769
y = 6.837021769

Simplifying
y = 6.837021769

Subproblem 2
y + -3.5 = -3.337021769

Simplifying
y + -3.5 = -3.337021769

Reorder the terms:
-3.5 + y = -3.337021769

Solving
-3.5 + y = -3.337021769

Solving for variable 'y'.

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

Add '3.5' to each side of the equation.
-3.5 + 3.5 + y = -3.337021769 + 3.5

Combine like terms: -3.5 + 3.5 = 0.0
0.0 + y = -3.337021769 + 3.5
y = -3.337021769 + 3.5

Combine like terms: -3.337021769 + 3.5 = 0.162978231
y = 0.162978231

Simplifying
y = 0.162978231

Solution
The solution to the problem is based on the solutions
from the subproblems.
y = {6.837021769, 0.162978231}