The positively charged core of an atom which is composed of positively charged protons in electrically neutral neutrons is a what?

Which number produces a rationale number when multiplied by 1/5

The difference between two numbers is one. three times the larger number minus two times the smaller number is 9. what are the two numbers

Suppose a gym membership has an initial enrollment fee of $75 and then a fee of $29 a month. which equation models the cost, c, of the gym membership for m months?