Respuesta :

Answer:

16

Explanation:

The equation for the term number n on a geometric sequence can be calculated as:

[tex]a_n=a_{}\cdot r^{n-1}[/tex]

Where r is the common ratio and a is the first term of the sequence.

So, if the seventh term of the sequence is 1/4 we can replace n by 7, r by 1/2, and aₙ by 1/4 to get:

[tex]\frac{1}{4}=a\cdot(\frac{1}{2})^{7-1}[/tex]

Then, solving for a, we get:

[tex]\begin{gathered} \frac{1}{4}=a(\frac{1}{2})^6 \\ \frac{1}{4}=a(\frac{1}{64}) \\ \frac{1}{4}\cdot64=a\cdot\frac{1}{64}\cdot64 \\ 16=a \end{gathered}[/tex]

So, the first term of the sequence is 16.