The sequence multiplies by 1/3.
Using the formula for a geometric sequence:
a(n) = a(1) * r^(n-1)
So...
a(n) = 648 * (1/3)^(n-1)
Plugging in 8 for n produces:
a(n) = 648 * (1/3)^(7)
Using a calculator, I find the answer to be 0.296296296...
The two expressions are not equivalent, you figure this out by solving both problems individually and seeing if the answer is the same as the other
Six numbers that are not perfect cubes 43, 0, 61, 15, 14, and 3
I did my best to explain it on graph paper. I hope this helps! Look at the attached picture.
