### Video Transcript

Given that 𝑓 of 𝑥 is equal to three to the power of 𝑥 minus eight, determine the value of 𝑓 of 𝑥 plus nine.

In our first equation, 𝑓 of 𝑥 is equal to three to the power of 𝑥 minus eight. When the input is 𝑥, the output is three to the power of 𝑥 minus eight. In order to work out the value of 𝑓 of 𝑥 plus nine, we need to substitute 𝑥 plus nine instead of 𝑥. This gives us three to the power of 𝑥 plus nine minus eight. By removing the parentheses or brackets, we can subtract eight from nine, giving us three to the power of 𝑥 plus one.

If 𝑓 of 𝑥 is equal to three to the power of 𝑥 minus eight, then 𝑓 of 𝑥 plus nine is equal to three to the power of 𝑥 plus one.