Plot solution region of a system of linear equation

Hi I am trying to find a suitable plot for the generic system of linear equation as follows.

    y = A+B*x;
    x = P+Q*y;

However, the constants A,B,P and Q are dependent on another set of parameters meu1, meu2, lambda1, lambda2. With given lambda1 and lambda2, I want to plot the variation of the solution expression of these straight lines, which is the following.

   ((A+B*P)/(1-B*Q),(P-A*Q)/(1-B*Q))

Can anyone help me with the plot? I am fine with both 2D and 3D plots.

Thanks.