Answer:
v = 3
Explanation:
7(v - 3) + 7v = 21
distribute the 7 into the parentheses
7v -21 +7v = 21
combine like terms
14v - 21 = 21
add 21 on both sides
14v + 21 - 21 = 21 + 21 which equals 14v = 42
divide both sides by 14 to isolate v
14v/14 = 42/14
v = 3
hope this helps :)