Finite geometric series
A geometric sequence begins \(-3, 9, -27, \ldots\). Calculate the sum of the first \(6\) terms. State the common ratio \(r\) and the value of \(S_6\).
Worked practice: sequences and series
Find the common change or ratio, then use it to calculate the requested term or sum.
Write a full answer
Now write the response in full, in your own words — this is what the exam asks for. The AI marks it on the same moves you built above (focus, evidence, technique, judgement) and gives feedback on reasoning, evidence, and expression.