Question

if r=-2 and t8=1536 find the first tirm
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Answer 1

Answer:

The first term is -12.

Step-by-step explanation:

The nth term of a GP is:

$T_{n}=ar^{n-1}$

a = first term

r = common ratio

It is given that the 8th term is 1536.

Compute the first term as follows:

$T_{8}=1536\\a(-2)^{8-1}=1536\\a\times-128=1536\\a=-\frac{1536}{128} \\a=-12$

Thus, the first term is -12.