42=-2(m+6)m

Solution for 42=-2(m+6)m equation:

Simplifying
42 = -2(m + 6) * m

Reorder the terms:
42 = -2(6 + m) * m

Reorder the terms for easier multiplication:
42 = -2m(6 + m)
42 = (6 * -2m + m * -2m)
42 = (-12m + -2m2)

Solving
42 = -12m + -2m2

Solving for variable 'm'.

Reorder the terms:
42 + 12m + 2m2 = -12m + 12m + -2m2 + 2m2

Combine like terms: -12m + 12m = 0
42 + 12m + 2m2 = 0 + -2m2 + 2m2
42 + 12m + 2m2 = -2m2 + 2m2

Combine like terms: -2m2 + 2m2 = 0
42 + 12m + 2m2 = 0

Factor out the Greatest Common Factor (GCF), '2'.
2(21 + 6m + m2) = 0

Ignore the factor 2.
Subproblem 1
Set the factor '(21 + 6m + m2)' equal to zero and attempt to solve:

Simplifying
21 + 6m + m2 = 0

Solving
21 + 6m + m2 = 0

Begin completing the square.

Move the constant term to the right:

Add '-21' to each side of the equation.
21 + 6m + -21 + m2 = 0 + -21

Reorder the terms:
21 + -21 + 6m + m2 = 0 + -21

Combine like terms: 21 + -21 = 0
0 + 6m + m2 = 0 + -21
6m + m2 = 0 + -21

Combine like terms: 0 + -21 = -21
6m + m2 = -21

The m term is 6m.  Take half its coefficient (3).
Square it (9) and add it to both sides.

Add '9' to each side of the equation.
6m + 9 + m2 = -21 + 9

Reorder the terms:
9 + 6m + m2 = -21 + 9

Combine like terms: -21 + 9 = -12
9 + 6m + m2 = -12

Factor a perfect square on the left side:
(m + 3)(m + 3) = -12

Can't calculate square root of the right side.

The solution to this equation could not be determined.

This subproblem is being ignored because a solution could not be determined.

The solution to this equation could not be determined.