Answer
Cameron forgot to do the same thing to the 9. Instead of dividing 3 by 3 and 9 by 3 he only divided 3 by 3.
Step-by-step explanation:
3/7 × 4/9
You can divide the 3 and 9 by 3 so you get 1/7 × 4/3.
Then you do 4 × 1 and 7 × 3.
Correct answer is 4/21