Work Step by Step
In order for the points to lie on the same line, they must have the same slope when paired with each other. For line GH, it is change in y over change in x so (3+1)/(2)=2. For GI, it is (3-7)/(5-7)=2. And for line HI it is (-1-7)/(3-7)=2 All of the slopes are the same so we can assert that the points lie on the same line.