Answer:
y = 5
Step-by-step explanation:
In order for an elimination to take place you have to eliminate a variable, in this situation the x variable can be eliminated,
(1). 3x + 9y = 21
-3x - 4y = 4
5y = 25
As you can see the x is eliminated.
Now we have to solve this,
(2). 5y = 25
5y/5 = 25/5
y = 5
So the answer is y = 5
