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Algebra / Systems of two linear equations in two variables Difficulty: Easy

x = 5

y = x - 8

Which of the following points x,y is the solution to the given system of equations in the xy-plane?

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Explanation

Choice B is correct. A solution to a system of equations in the xy-plane is a point x,y that lies on the graph of each equation in the system. The first equation given is x = 5 . Substituting 5 for x in the second given equation yields y=5-8, or y = -3 . It follows that in the xy-plane, the point 5,-3 lies on the graph of each equation in the system. Therefore, the solution to the given system of equations in the xy-plane is 5,-3.

Choice A is incorrect. The point 0,0 doesn't lie on the graph of either equation in the given system.

Choice C is incorrect. The point 5,-8 doesn't lie on the graph of the second equation in the given system.

Choice D is incorrect. The point 5,8 doesn't lie on the graph of the second equation in the given system.