Question

What is the 7th term of the geometric sequence below? 7, -14,28, -56, А -448 b b -896 с 448 D 896

Answer 1

Given the sequence:

7, -14, 28, -56,

To find the 7th term of the geometric sequence, use the formula below:

`a_n=ar^((n-1))`

where,

a is the first term = 7

n is the number of terms = 7

r = common ratio =

`r\text{ = }\frac{\sec ond\text{ term}}{\text{first term}}\text{ = }(-14)/(7)=\text{ -2}`

Thus, we have:

`\begin{gathered} a_7=\text{ 7(}-2^((7-1))) \\ \\ \text{ = 7 }(-2^6) \\ \\ \text{ = }7(-64) \\ \\ \text{ = }-448 \end{gathered}`

The 7th term is -448

ANSWER:

A) -448