Algebra  solving linear equations w/ substitution
posted by Samantha .
The question in the book reads:
"Suppose you try to solve a system of linear equations using substitution and get this result. How many solutions does each system have?"
1)x=2
2)y=12
3)6=x
4)8=8
5)7=y
6)5=3
I understand #3 and #6, but I do not understand how to know how many solutions there are to #1,2,3,or 5.

1)one solution
2)one solution
4)infinite solutions
5)one solution