Answer:
3/7
Explanation
This problem requires familiarity with Order of Operations rules. In this case we must do any calculations within parentheses first, followed by mult. and div., and only then do we do add'n. and subtr'n. I have not mentioned exponentiation because there's none in this problem.
Address the operations within parentheses first:
( 1/2 +2 1/2 ) = 1/2 + 5/2 = 6/2 = 3 (after converting 2 1/2 into the improper fraction 5/2)
Next, the middle term: (1/2)(2/3) = 1/3
Finally, the last term: OK as is: 1/3
Then ( 1/2 +2 1/2 )÷7 becomes 3/7.
Next: 3/7 - 1/3 + 1/3 = 3/7 (answer)