OG详解-OG3 数学2 Q10

Choice D is correct. Since the graphs of the equations in the given system intersect at the point (x, y), the point (x, y) represents a solution to the given system of equations. The first equation of the given system of equations states that x = 8. Substituting 8 for x in the second equation of the given system of equations yields y = 8² + 8, or y = 72. Therefore, the value of y is 72.
Choice A is incorrect. This is the value of x , not y. Choice B is incorrect and may result from conceptual or calculation errors. Choice C is incorrect and may result from conceptual or calculation errors.