0=60+64x+12x^2

Solution for 0=60+64x+12x^2 equation:

Simplifying
0 = 60 + 64x + 12x2

Solving
0 = 60 + 64x + 12x2

Solving for variable 'x'.

Combine like terms: 0 + -60 = -60
-60 + -64x + -12x2 = 60 + 64x + 12x2 + -60 + -64x + -12x2

Reorder the terms:
-60 + -64x + -12x2 = 60 + -60 + 64x + -64x + 12x2 + -12x2

Combine like terms: 60 + -60 = 0
-60 + -64x + -12x2 = 0 + 64x + -64x + 12x2 + -12x2
-60 + -64x + -12x2 = 64x + -64x + 12x2 + -12x2

Combine like terms: 64x + -64x = 0
-60 + -64x + -12x2 = 0 + 12x2 + -12x2
-60 + -64x + -12x2 = 12x2 + -12x2

Combine like terms: 12x2 + -12x2 = 0
-60 + -64x + -12x2 = 0

Factor out the Greatest Common Factor (GCF), '-4'.
-4(15 + 16x + 3x2) = 0

Ignore the factor -4.
Subproblem 1
Set the factor '(15 + 16x + 3x2)' equal to zero and attempt to solve:

Simplifying
15 + 16x + 3x2 = 0

Solving
15 + 16x + 3x2 = 0

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

Divide each side by '3'.
5 + 5.333333333x + x2 = 0

Move the constant term to the right:

Add '-5' to each side of the equation.
5 + 5.333333333x + -5 + x2 = 0 + -5

Reorder the terms:
5 + -5 + 5.333333333x + x2 = 0 + -5

Combine like terms: 5 + -5 = 0
0 + 5.333333333x + x2 = 0 + -5
5.333333333x + x2 = 0 + -5

Combine like terms: 0 + -5 = -5
5.333333333x + x2 = -5

The x term is 5.333333333x.  Take half its coefficient (2.666666667).
Square it (7.111111113) and add it to both sides.

Add '7.111111113' to each side of the equation.
5.333333333x + 7.111111113 + x2 = -5 + 7.111111113

Reorder the terms:
7.111111113 + 5.333333333x + x2 = -5 + 7.111111113

Combine like terms: -5 + 7.111111113 = 2.111111113
7.111111113 + 5.333333333x + x2 = 2.111111113

Factor a perfect square on the left side:
(x + 2.666666667)(x + 2.666666667) = 2.111111113

Calculate the square root of the right side: 1.452966315

Break this problem into two subproblems by setting 
(x + 2.666666667) equal to 1.452966315 and -1.452966315.

Subproblem 1
x + 2.666666667 = 1.452966315

Simplifying
x + 2.666666667 = 1.452966315

Reorder the terms:
2.666666667 + x = 1.452966315

Solving
2.666666667 + x = 1.452966315

Solving for variable 'x'.

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

Add '-2.666666667' to each side of the equation.
2.666666667 + -2.666666667 + x = 1.452966315 + -2.666666667

Combine like terms: 2.666666667 + -2.666666667 = 0.000000000
0.000000000 + x = 1.452966315 + -2.666666667
x = 1.452966315 + -2.666666667

Combine like terms: 1.452966315 + -2.666666667 = -1.213700352
x = -1.213700352

Simplifying
x = -1.213700352

Subproblem 2
x + 2.666666667 = -1.452966315

Simplifying
x + 2.666666667 = -1.452966315

Reorder the terms:
2.666666667 + x = -1.452966315

Solving
2.666666667 + x = -1.452966315

Solving for variable 'x'.

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

Add '-2.666666667' to each side of the equation.
2.666666667 + -2.666666667 + x = -1.452966315 + -2.666666667

Combine like terms: 2.666666667 + -2.666666667 = 0.000000000
0.000000000 + x = -1.452966315 + -2.666666667
x = -1.452966315 + -2.666666667

Combine like terms: -1.452966315 + -2.666666667 = -4.119632982
x = -4.119632982

Simplifying
x = -4.119632982

Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {-1.213700352, -4.119632982}
Solution
x = {-1.213700352, -4.119632982}