c is the correct answer to your problem
6480 is the next one, and the second next one is -38880. You can determine this by multiplying the number twice by 36.
Answer:
a = ±sqrt(3)
Step-by-step explanation:
a×a×a=a+a+a
Simplifying each side
a^3 = 3a
Divide each side by a
a^3 /a = 3a/a
a^2 = 3
Take the square root of each side
sqrt(a^2) = ±sqrt(3)
a = ±sqrt(3)