Answer:
k = 10
Explanation:
9 - 5k = 12 - (6k + 7)
open the parenthesis
9 - 5k = 12 - 6k - 7
add 6k to both sides of the equation
9 - 5k + 6k = 12 - 6k - 7 + 6k
combine like terms
9 + k = 19
subtract 9 from both sides of the equation
9 + k - 9 = 19 - 9
k = 10