I am struggling with my math

Question

Given the first term and the common ratio of a geometric sequence, find the term named BY USING THE APPROPRIATE FORMULA. DO NOT WRITE A LIST OF TERMS TO FIGURE IT OUT. NO CREDIT WILL BE GIVEN!

a1=−4, r =−4, find a9

Answer 1

The formula for a the nth geometric series term is a₁(r)^n-1 = a_n You evaluate (-4)(-4)⁸

Answer 2

The formula to find out nth term of a G.P. is ar^n , where a is the first term and r is the common ratio.

Here the first term is -4 and the common ratio is also -4. So substituting the value in the formula for a9 we got -262144

Answer 3

a₉ = a₁r⁸ _{= -4(-4)}⁸ = - 262144