Answer:2M+1
Step-by-step explanation: The 2 would be used to double Mark's age since the question says Joey is twice Marks age. The +1 is used to add one more year after multiplying Mark's age by 2 since the question says Joey is one year older. For example if Mark's age is 2 then plug it into the equation 2(2)+1 which would make Joey's age 5. Because the 2 would double the M in this case 2 and then add a 1 to his age after because of order of operations.