Step-by-step explanation:
9) -12=2+5v+2v
-12-2=7v
-14=7v
v=-2.
10) 3=x+3-5x.
-4x=0
x=0
11) -12=3-2k-3k
-12-3=-5k
-15=-5k
k=3.
hope this helps you.