ContourPlot[Evaluate@{#}, {x, -5, 10}, {y, -8, 10},
AxesOrigin -> {0, 0}, Frame -> False, Axes -> True,
AxesOrigin -> {0, 0}, PlotLegends -> Automatic,
Epilog -> {{Purple,
Line[{{0, 0},
pt = CoefficientArrays[#, {x, y}][[-1]] // Normal}]}, {Red,
PointSize@0.02, Point[pt]}}] & /@ (ls = {x + 2 y - 5 == 0,
2 x - 3 y - 6 == 0, 2 x - 3 y + 6 == 0,
3 x - 8 y - 10 == 0, -3 x - 7 y + 8 == 0, -3 x - 7 y - 8 == 0})
PlotLegends Not Showing for Individual Equations in Mathematica ContourPlot
