Because I am not exactly sure what war you are talking about, I will answer the question as if it were World War II. The Attack on Pearl Harbor is the main reason the U.S. joined the war (WWII).
I hope this helps.
Answer:
substitute y and x in each question as 0 and get your variables and find the point where they intersect
Explanation:
the first line has to go through(0,-3)
the second line has to go through (0,2)
you can find other co ordinates for the line to pass through but inputing other numbers.