<prompt> Chaguo za kukokotoa fx zinatoshelezafx - 2 f kushoto frac1x kulia 4xkwa zote x neq 0. Tafuta f2.  <response>: Kuweka x 2, tunapataf2 - 2 f kushoto frac12 kulia 16.Kuweka x 12, tunapataf kushoto frac12 kulia - 2f2 2.Kutatua milinganyo hii kama mfumo katika f2 na f left frac1 2 kulia, tunapata f2 -frac203 na f left frac12 kulia -frac 343. 