Answer:
x=28
Explanation:
I'm not sure if the answer is correct but what I did was I took 14 and x and put it in fraction form (14 over x) and did the same for 21 and 42 (21 over 42). Then I cross multiplied 14 and 42 which got me 588 then divided that by 21 which gave the final answer of 28. If the answer is incorrect feel free to tell. Hope this helps :)