Which expression is a sum of cubes?

a) -27a^ b^6 + 8a^9 b^12
b) -9a^3 b^6 + a^9 b^10
c) 9a^3 b^6 + 8a^9 b^12
d) 27a^3 b^6 + 8a^9 b^12

Asequence {an} is defined recursively, with a1 = 1, a2 = 2 and, for n > 2, an = an-1 an-2 . find the term a241

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'

The bolo cavern outside of vandalia is 421 ft below sea level. a little more than75 miles away. mt owens is 7295 feet above sea level. what is the difference in elevation between the bolo cavern and mt owens?