Answer:
In a problem where you
calculate the "solution" to a "system of equations"
one of three things will happen....
#1) you end up with x=3 , or y=7 .. or something like that
if that happens then there is ONE SOLUTION
#2) you end up with 5=5, or 7=7 , or 0=0
in this case the lines are the same and you have "all real numbers" as the solution (there are an infinite number of solutions, the lines are the same line)
#3) you end up with 1=2, 0=5, 2=7, etc. this is impossible, there are no solutions ... the lines are parallel
Explanation: