BYU Math 110 Final Exam

What equation(s) would I use to solve: Find a10 if a2 = 5 and r = 3 - An = ar^(n-1) and I would solve it like this: A2 = ar^(2-1) = ar^1 A10 = ar^(10-1) = ar^9 Which leaves us with a^8 Then after solving for R's exponent, I would plug in the values of a2 and r to find a10: a10 = (a2)(r^8) a10 = (5)(3^8) = 32805 What equation(s) would I use to find the answer to this problem: A5 = (8/375) A8 = (64/46,875) Determine A and R - an = ar^(n-1) First I'd solve for r by diving the equation for a8 by the equation for a5. (64/46875) = ar^(8-1) = ar^7 divided by (8/375) = ar^5-1 = ar^4 Therefore: 8/125 = r^3 and r = 2/5 Once I have R, I'd solve for A by plugging R into one of the equations. So, a5 = (8/375) = a(2/5)^5-1 turns out to be: a = 5/6