Find the 19

Find the 1st term of the GP ___, -6, 18, -54.

Correct answer:

a1 =  2

Step-by-step explanation:

a2=−6 a3=18 a4=−54  r=a3/a2=18/(−6)=−3  a1=a2/r=(−6)/(−3)=2

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