[tex]3x+y=4\ \ \ \ \ \ ..............equation(1)\\x-3y=4\ \ \ \ \ \ ..............equation(2)\\\\ Using~equation~(2), \\\\
x-3y=4\\x=4+3y\\\\Now,\ using\ the\ value\ of\ x\ in\ equation\ (1),\ we\ get,\\\\(4+3y)-3y=4\\\\4=4[/tex]
Since all the variables cancel out and the coefficient equal to eachother, this system of equation has infinitely many solutions!
