Question 62794
Solving for y for the last two equations we get {{{y=expr(8/3)x-8}}} and {{{y=-expr(3/4)x+6}}}.  The graph of all three lines is below; they don't intersect.  Any two of the lines do, but I don't know what exactly you're looking for.
{{{graph(200,200,-2,10,-5,5,2x/3-4,8x/3-8,-3x/4+6)}}}