Answer:
2/3
Step-by-step explanation
21 is a multiple of 7. To add fractions you must have the same denominator. 7 times 3 is 21. So multiple the whole fraction, both numerator and denominator(2 and 7) by 3 to get 6/21. From there just add 6/21 and 8/21 together to get 14/21 then in they have a GCF(greatest common factor), which in this case is 7. Divide it by the GCF to simplify the fraction.
Hope this helps!
