Answer:
a³ = -357911/5832.
Explanation:
We can use the given equation to find the value of n, and then use it to find the value of a³.
a¹ = 13 and a = ⁿ⁻¹ - 4
Substituting the value of a in terms of n in the first equation, we get:
ⁿ⁻¹ - 4 = 13
ⁿ⁻¹ = 13 + 4
ⁿ⁻¹ = 17
ⁿ = 18
Now, substituting the value of n in the equation a = ⁿ⁻¹ - 4, we get:
a = 18⁻¹ - 4
a = 1/18 - 4
a = -71/18
Finally, to find a³, we can cube the value of a:
a³ = (-71/18)³
a³ = -357911/5832
Therefore, a³ = -357911/5832.