Answer:
15/13
Step-by-step explanation:
Prime factor is a factor that is a prime number.
Prime factors of :
8 : 2 × 2 × 2. Also can be written as

12 : 2 × 2 × 3. Also can be written as

20 : 2 × 2 × 5. Also can be written as

30 : 2 × 3 × 5
56 : 2 × 2 × 2 ×7. Also can be written as

70 : 2 × 5 × 7
You can find all of them by using Factor Tree [ as shown in the picture] or Dividing by prime numbers.
Answer:
5n-28
Step-by-step explanation:
28-6n+7(2n-8)-3n
28-6n+14n-56-3n
28+8n-56-3n
28-56+8n-3n
-28+5n
5n-28
It will be 256.20 I hope I helped