42k-4k^2=0

Solution for 42k-4k^2=0 equation:

Simplifying
42k + -4k2 = 0

Solving
42k + -4k2 = 0

Solving for variable 'k'.

Factor out the Greatest Common Factor (GCF), '2k'.
2k(21 + -2k) = 0

Ignore the factor 2.
Subproblem 1
Set the factor 'k' equal to zero and attempt to solve:

Simplifying
k = 0

Solving
k = 0

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

Simplifying
k = 0
Subproblem 2
Set the factor '(21 + -2k)' equal to zero and attempt to solve:

Simplifying
21 + -2k = 0

Solving
21 + -2k = 0

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

Add '-21' to each side of the equation.
21 + -21 + -2k = 0 + -21

Combine like terms: 21 + -21 = 0
0 + -2k = 0 + -21
-2k = 0 + -21

Combine like terms: 0 + -21 = -21
-2k = -21

Divide each side by '-2'.
k = 10.5

Simplifying
k = 10.5
Solution
k = {0, 10.5}