Question 795404
-(k + 12) = 6 + (-12)
-k - 12 = 6 - 12
-k - 12 = -6
-k + k - 12 + 6 = k - 6 + 6
-12 + 6 = k
-6 = k

check:
-(-6 + 12) = 6 - 12
6 -12 = 6 -12
-6 = -6