Is { (8,5) , (7,5) , (6,2) , (8,3) , (1,-4), (-4,6)} a function? why?

No.  because you have One domain value that  says 2 different numbers

Step-by-step explanation:

functions cannot have  f(8) = 5  and f(8) = 3  at the same time

because  then f(8)  is not equal to f(8)  it cannot be confusing.

walter needs to make at least 5 more cookies but no more than 40. 5 ≥ x ≥ 40;

step-by-step explanation:

walter has to make a minimum of 20 cookies. he already has 15 cookies made, so he must make 5 more to meet the minimum.

the maximum amount of cookies he can make is 55. he already has 15, so he has to make no more than 40 more cookies to meet the maximum.

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons