2(3y-7)-5y(2-y)=

Solution for 2(3y-7)-5y(2-y)= equation:

Simplifying
2(3y + -7) + -5y(2 + -1y) = 0

Reorder the terms:
2(-7 + 3y) + -5y(2 + -1y) = 0
(-7 * 2 + 3y * 2) + -5y(2 + -1y) = 0
(-14 + 6y) + -5y(2 + -1y) = 0
-14 + 6y + (2 * -5y + -1y * -5y) = 0
-14 + 6y + (-10y + 5y2) = 0

Combine like terms: 6y + -10y = -4y
-14 + -4y + 5y2 = 0

Solving
-14 + -4y + 5y2 = 0

Solving for variable 'y'.

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

Divide each side by '5'.
-2.8 + -0.8y + y2 = 0

Move the constant term to the right:

Add '2.8' to each side of the equation.
-2.8 + -0.8y + 2.8 + y2 = 0 + 2.8

Reorder the terms:
-2.8 + 2.8 + -0.8y + y2 = 0 + 2.8

Combine like terms: -2.8 + 2.8 = 0.0
0.0 + -0.8y + y2 = 0 + 2.8
-0.8y + y2 = 0 + 2.8

Combine like terms: 0 + 2.8 = 2.8
-0.8y + y2 = 2.8

The y term is -0.8y.  Take half its coefficient (-0.4).
Square it (0.16) and add it to both sides.

Add '0.16' to each side of the equation.
-0.8y + 0.16 + y2 = 2.8 + 0.16

Reorder the terms:
0.16 + -0.8y + y2 = 2.8 + 0.16

Combine like terms: 2.8 + 0.16 = 2.96
0.16 + -0.8y + y2 = 2.96

Factor a perfect square on the left side:
(y + -0.4)(y + -0.4) = 2.96

Calculate the square root of the right side: 1.720465053

Break this problem into two subproblems by setting 
(y + -0.4) equal to 1.720465053 and -1.720465053.

Subproblem 1
y + -0.4 = 1.720465053

Simplifying
y + -0.4 = 1.720465053

Reorder the terms:
-0.4 + y = 1.720465053

Solving
-0.4 + y = 1.720465053

Solving for variable 'y'.

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

Add '0.4' to each side of the equation.
-0.4 + 0.4 + y = 1.720465053 + 0.4

Combine like terms: -0.4 + 0.4 = 0.0
0.0 + y = 1.720465053 + 0.4
y = 1.720465053 + 0.4

Combine like terms: 1.720465053 + 0.4 = 2.120465053
y = 2.120465053

Simplifying
y = 2.120465053

Subproblem 2
y + -0.4 = -1.720465053

Simplifying
y + -0.4 = -1.720465053

Reorder the terms:
-0.4 + y = -1.720465053

Solving
-0.4 + y = -1.720465053

Solving for variable 'y'.

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

Add '0.4' to each side of the equation.
-0.4 + 0.4 + y = -1.720465053 + 0.4

Combine like terms: -0.4 + 0.4 = 0.0
0.0 + y = -1.720465053 + 0.4
y = -1.720465053 + 0.4

Combine like terms: -1.720465053 + 0.4 = -1.320465053
y = -1.320465053

Simplifying
y = -1.320465053

Solution
The solution to the problem is based on the solutions
from the subproblems.
y = {2.120465053, -1.320465053}