First we'll substitute
with 

Then we can separate this.

Then we'll solve this.



Then we'll plug in to find the extraneous solutions (if any)

Substitue y=3x into the other equation to get 3x=-x+4. Solve this to get 4x=4 therefore x=1.
knowing this, y=3
Add all the number then divided by as many numbers as you added
Answer:
Step-by-step explanation: