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What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

Kayla has a $500 budget for the school party.she paid $150 for the decorations.food will cost $5.50 per student. what inequality represents the number of students,s, that can attend the party?

Let f(x) = 3 − x . find the average rate of change of f(x) from x = a to x = a + h and simplify your answer so that no single factor of h is left in the denominator.