<span>When creating a subset of 5 elements from 7 elements, order should not matter. Therefore, we use the combination formula over the permutation formula.
The combination formula given n elements total and r elements used is n! / [r!*(n-r)!]. Substituting 7 for n and 5 for r, we get:
7! / (5!*2!) = 7*6 / 2 = 21
21 subsets can be created</span>
There are no real solutions
Answer:
We just need to evaluate and get f(2i)=0, f(-2i)=0.
Step-by-step explanation:
Since 
, then 
, and we can apply this when we evaluate 
for 2i and -2i.
First we have:
Which shows that 2i is a zero of f(x).
Then we have:
Which shows that -2i is a zero of f(x).
I’m not sure about this one I’m sorry I couldn’t help
