Answer: 11 and 3/10
Step-by-step explanation: first fing how many times 2 fits into 21 wich it fits 10 times so it would be 10 and 1/2 change 10 and 1/2 to 10 and 5/10 by multiplying it by 2. Then change 4/5 to 8/10 by multiplying by 2 then add 10 and 5/10 to 8/10 simplify if nessesary