21k^2+50k+25=0

Solution for 21k^2+50k+25=0 equation:

Simplifying
21k2 + 50k + 25 = 0

Reorder the terms:
25 + 50k + 21k2 = 0

Solving
25 + 50k + 21k2 = 0

Solving for variable 'k'.

Factor a trinomial.
(5 + 3k)(5 + 7k) = 0

Subproblem 1
Set the factor '(5 + 3k)' equal to zero and attempt to solve:

Simplifying
5 + 3k = 0

Solving
5 + 3k = 0

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

Add '-5' to each side of the equation.
5 + -5 + 3k = 0 + -5

Combine like terms: 5 + -5 = 0
0 + 3k = 0 + -5
3k = 0 + -5

Combine like terms: 0 + -5 = -5
3k = -5

Divide each side by '3'.
k = -1.666666667

Simplifying
k = -1.666666667
Subproblem 2
Set the factor '(5 + 7k)' equal to zero and attempt to solve:

Simplifying
5 + 7k = 0

Solving
5 + 7k = 0

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

Add '-5' to each side of the equation.
5 + -5 + 7k = 0 + -5

Combine like terms: 5 + -5 = 0
0 + 7k = 0 + -5
7k = 0 + -5

Combine like terms: 0 + -5 = -5
7k = -5

Divide each side by '7'.
k = -0.7142857143

Simplifying
k = -0.7142857143
Solution
k = {-1.666666667, -0.7142857143}