If I remember correctly, the solutions are only on the solid line or in the shaded area? therefore Answers could be:
6.) (-3,0.5) (-4,0) (-2,0) (-2,-5) (-3,-5) (-4,-1) (-3,-1) (-2,-1)
7.) (-1,0) (-2,0) (-3,0) (0,-1) (-4,-1)
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