Answer:
The correct answer was
1=Zero product property
2=square root property
Step-by-step explanation:
Let's begin by listing out the information given to us:
There are four students: n = 4
Number of students to be selected: r = 2
To calculate the combination of 2 students to be chosen, we use:

Therefore, there 12 possible combinations from these
Answer:
answer = 21
Step-by-step explanation:
2n - 2 = 40
2n - 2 + 2 = 40 + 2
2n = 42
2n/2 = 42/2
n = 21