Question

can you tell me the answer step by step​

Answer 1

Answer:

7/9

Step-by-step explanation:

7^n+2-3×7^n+1

7^n×7^2-3×7^n×7^1 =>7^n×7^2-21×7^n

here 7^n is commom so

7^n(7^2-21)

20×7^n-2×7^n

7^n(20-2)

7^n(49-21)/7^n(20-2)

28/18=7/9