SubArea: Geometric sequencesLevel: BProject ID: 9000072806Source Problem: 2010004901Accepted: 1Clonable: 1Easy: 1The following numbers form a geometric sequence. Find \(x\). \[ 2\, ,\ 1\, ,\ a\, ,\ x \]\(\frac{1} {4}\)\(\frac{1} {2}\)\(-\frac{1} {2}\)\(- 1\)
