If you want to share 747 pounds between Tom and Ben in ratio 2:7, then you should divide 747 by 2+7=9 in order to determine how many pounds will one part of 9 parts.
747:9=83.
Then Tom should get 2 such parts, that is 83·2=166 pounds and Ben should get 7 such parts, that is 83·7=581 pounds.
Answer: you should give 166 pounds to Tom and 581 pounds to Ben.