Respuesta :

x = 3, y² = -5x -12, x² + y² =81. are all not functions. the others are functions.

Step-by-step explanation:

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A function assigns the values. The correct options are C and E.

What is a Function?

A function assigns the value of each element of one set to the other specific element of another set.

An equation is said to be a function if for each different value of x(input) it should give a different output. Therefore, for different inputs of x, the value of the output y should be different and unique. Also, the values if the equation produces the same output for two values of x it also said to be a function.

A.)

x = 3, since for every value of x the value is 3, which is not possible. Hence, this is not a function.

B.)

x² + y² = 81

For the given equation if the value of x is given as 0, the value of y will be,

x² + y² = 81

0² + y² = 81

y² = 81

y = ±√81

y = -9, 9

Hence, this can not be a function.

C.) y = -x + 11

For the given equation if the value of x is kept anything the value of y will be different. Thus, this is a function.

D.)

y² = -5x - 12

For the given equation if the value of x is given as less than -2.4, there will be two values of y. Thus, the given equation is not a function.

E.)

y = 2x² - 6x + 4

The given function will return will the same value of y for 2 different values of x. Hence, this is a function.

F.)

y = -7

Since the given equation can only have the value of y as 7. Therefore, it is not a function.

Hence, the equations that are a function are y = -x + 11 and  y = 2x² - 6x + 4.

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