Bobby is constructing a table of values that satisfies the definition of a function...

Question

Bobby is constructing a table of values that satisfies the definition of a function. What number(s) can be placed in the empty cell so that the table of values satisfies the definition of a function?

 

*Numbers are put in aligning to the corresponding output*

 

Input=   {-13, -4, -1, 0, 11, 17, 20, ?}

Output= {-15, -2, 5, -9, -1, 5, -11, 13}

 

The numbers to pick from for ? are -5, -1, 0, 2, 11, and 17. More than one number can be selected, please help very confused and frustrated!

Answer 1

The restriction for the pairs of a function is that each input value has a unique output value.  The output value is 13.  The choices for input cannot be -1, 0, 11, or 17, which have already been paired, so that either -5 or 2 may be used as an input value.