text: There are three possibilities when finding the solution to a system of equations:\n1.  There are no solutions,\n2.  There is only one (unique) solution, and\n3.  There are infinitely many solutions.\n\nAn example of 1:\n\nx+y = 3\n2x+2y = 4\nHere there is no x and y pair that satisfy both equations\n\nAn example of 3:\n2x+3y = 5\n4x+6y = 10\nHere there are infinitly many solutions ((1,1), (2,1/3), (3,-1/3), and so on.\n\nFor your second question:\n\ny = mx + b\n\nSince you already have m (the slope), then plug in the x and y value to get b.\n\n3 = 2(1) + b\nso b = 3-2 = 1\nso y = 2x + 1