42=-3(2+4k)

Solution for 42=-3(2+4k) equation:

Simplifying
42 = -3(2 + 4k)
42 = (2 * -3 + 4k * -3)
42 = (-6 + -12k)

Solving
42 = -6 + -12k

Solving for variable 'k'.

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

Add '12k' to each side of the equation.
42 + 12k = -6 + -12k + 12k

Combine like terms: -12k + 12k = 0
42 + 12k = -6 + 0
42 + 12k = -6

Add '-42' to each side of the equation.
42 + -42 + 12k = -6 + -42

Combine like terms: 42 + -42 = 0
0 + 12k = -6 + -42
12k = -6 + -42

Combine like terms: -6 + -42 = -48
12k = -48

Divide each side by '12'.
k = -4

Simplifying
k = -4