Answer:
22
Step-by-step explanation:
add everything in the parentheses first, then multiply by 1/2 (or divide by 2)
(28 + 7 + 6 + 3) x 1/2 = 44 x 1/2 = 22
I think it could be 13,17, and 15.
If I am wrong then I am sorry
Product means multiply, a number means any variable so 6x is the answer