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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.
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
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