Multiply the bracket by 2
-4K+2(5k- 6)=-3k-39
-4K+10K-12= -3K-39
6K-12= -3K-39
Move -3K to the other side. Sign changes from -3K to +3K.
6K+3K-12= -3K+3K-39
9K-12= -39
Move -12 to the other side. Sign changes from -12 to +12.
9K-12+12= -39+12
9K= -27
Divide by 9
9K/9= -27/9
K= -3
Answer : K= -3
