15x + 5y = 5
3x + y = 1
[tex]15x + 5y = 5 \\
3x + y = 1 \\ \\ 15x + 5y = 5 \\ - 5(3x + y = 1) \\ \\ 15x+5y=5 \\ - 15x - 5y = - 5\\ - - - - - - - - \\0 + 0 = 0 \\ \\ [/tex]
this has an infinite number of solution. (0 = 0)
in graph, this is an overlapping lines
