Discount Perpetuities - Constantly growing CF

Hey guys,

I am taking my first steps in valuation and have problems with the solutions to 2 questions. Both questions described constantly growing cash flows in the future, which I had to discount to the present value. However, they were discounted differently by including the g (growth rate) in different ways:

Solutions to question 1: CF*(1+g) / (r-g)

Solutions to question 2: CF / r-g

Do you see the difference? The cash flow is constantly increased in solution 1 while the growth is also reflected in the discount rate. In solution 2, the growth is only reflected in the discount rate.

Can you help me? When do I use what? For my understanding, the growth of the cashflow is already reflected in the denominator and is not required in the numerator..

Best regards and thank you!