question - if the 3rd and 9th term of a geometric series with a positive common ratio are -3 and -192 respectively, determine the value fo the first term, a.(adsbygoogle = window.adsbygoogle || []).push({});

I kno we using

a_n=a_1r^n-1

From that i got this :

-3 = a_1r^2

-192 = a_1r^8

But I dont kno how I can solve for r or a_1... I also don't know if I even did it right

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# Geometric sequence, determining the value of the first term

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