they would like to add, subtract, or multiply these numbers. Perform the chosen operation on the values, showing the operation being performed $($use numbers in order even if a negative value is produced!$)$ Write three functions, one for each mathematical operation. For example, if this was the input given: What is the first number?: $3$ What is the second number?: $5$ Choose an operation $($add$,$ subtract, multiply$)$: multiply The following output should be given: $3*5=15$ Notes: Use the user input values of add, subtract, and multiply. Do not use the variable name operator. Be sure to print a notice if an invalid operation is chosen!