Question

Find the common ratio of the geometric sequence with a first term -8 and a sixth term -1944

Answer 1

`\bf \begin{array}{llll} term&value\\ \textendash\textendash\textendash\textendash\textendash\textendash&\textendash\textendash\textendash\textendash\textendash\textendash\\ 1&-8\\ 2&(-8)r\\ 3&(-8\cdot r)r\to &-8r^2\\ 4&(-8r\cdot r)r\to &-8r^3\\ 5&(-8r\cdot r\cdot r)r\to &-8r^4\\ 6&(-8r\cdot r\cdot r\cdot r)r\to &-8r^5 \end{array} \\\\ \textit{we know the 6th term is -1944} \qquad thus\implies -1944=-8r^5`

solve for "r"