We want to find the seventh term of the given . First we will find its . Let's start by calculating the .
We will now use the common ratio
-5 and the first term
-1 to write the formula.
an=a1rn−1⇔an=-1⋅(-5)n−1
Finally, to calculate the seventh term we will substitute
7 for
n in our formula.
an=-1⋅(-5)n−1
a7=-1⋅(-5)7−1
a7=-15625