42=3(k+9)

Solution for 42=3(k+9) equation:

Simplifying
42 = 3(k + 9)

Reorder the terms:
42 = 3(9 + k)
42 = (9 * 3 + k * 3)
42 = (27 + 3k)

Solving
42 = 27 + 3k

Solving for variable 'k'.

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

Add '-3k' to each side of the equation.
42 + -3k = 27 + 3k + -3k

Combine like terms: 3k + -3k = 0
42 + -3k = 27 + 0
42 + -3k = 27

Add '-42' to each side of the equation.
42 + -42 + -3k = 27 + -42

Combine like terms: 42 + -42 = 0
0 + -3k = 27 + -42
-3k = 27 + -42

Combine like terms: 27 + -42 = -15
-3k = -15

Divide each side by '-3'.
k = 5

Simplifying
k = 5