Respuesta :

12+5v−12−2v=2v−9−12−2v Step 1
12−12+5v−2v=2v−2v−9−12. Step 2 
0+(5−2)v=0−21.              Step 3 
3v=−21 Step 4 

Now you have to divide 
3v3=−213

3v3=−7

v=−7

12 + 5v = 2v - 9
Subtract 12 from both sides.

5v = 2v - 21
Subtract 2v from both sides.

3v = -21
Divide both sides by 3.

v = -7