Hope this helps.
If not, go to: https://www.mathportal.org/calculators/financial-calculators/simple-interest-calculator.php
What is the series you are referring too?
Your equation would be t +25=57 because we don’t know how many necklaces Stacy made so we use T to plug it in and solve
the answer is 16
8^(4/3) can be written in different ways. You can first simplify it by breaking the exponents down into 1/3 and 4. You can write it as (8^1/3)^4 (it still means the same thing). When you raise something to the one over something fraction, the denominator tells you what the root is. Because it says 1/3, it means that you're finding the cube root of something. So you can rewrite it as (3√8)^4 (the three should be sitting on top of the sign to signify that it's cube root). You then just solve from there. The cube root of 8 is 2 (2*2*2=8) so it'll simplify to (2)^4. You then solve it from there and get 16 as your answer (2*2*2*2=16).