Answer:
Option a: ∑⁵(n−1)! is the correct answer.
n=²
Step-by-step explanation:
Option a: ∑n=25(n−1)
By substituting the values of n and expanding the summation, we have,
(2−1)!+(3−1)!+(4−1)!+(5−1)!
Subtracting, we have,
1!+2!+3!+4!
Expanding the factorial,
1+(2∗1)+(3∗2∗1)+(4∗3∗2∗1)
Simplifying, we get,
1+2+6+24
Thus, the summation ∑⁵ (n−1)! represents the
n=2
series 1+2+6+24
Hence, Option a is the correct answer.
