Step-by-step explanation:
1. secx / cscx
2. sinx /cosx
Answer:
3(3a - 6b + 7c )
The greatest common factor of 9, 18 and 21 is 3
Factor out 3 from each term
9a - 18b + 21c
= 3(3a - 6b + 7c) ← in factored form
