Since it starts with 2 envelopes, subtract 2 from 17 to get how many and in all 3 packs.
17 - 2 = 15
Now, we divide that number by 3 to get how many are in each envelope.
15 / 3 = 5
There are 5 envelopes in each pack.
First we'll substitute
with 

Then we can separate this.

Then we'll solve this.



Then we'll plug in to find the extraneous solutions (if any)

Answer: 81
Step-by-step explanation: Because, (-3)^4=-3*-3*-3*-3=-(-81)=81
X and y are switched and y times -1 so
reflection across the x=y line (identiy line)
and since the x place it times -1, that is a reflection across y axis
so reflection across x=y line and y axis
The mode is 4 because it is the number that shows up the most.