(1+1/а³):(1-1/а+1/а²) = ((а³+1)/а³):((а²-а+1)/а²) = (а³+1)/а³ * а²/(а²-а+1) =
(а³+1) / (а³-а²+1) = (2³+1) / (2³-2²+2) = 9/6 = 2/3 =1,5
((х/у - 9у/х)) / ((х/у + 9у/х + 6)) = ((х²-9у²)/ух) / ((х²+6ху+9у²)/(ху)) = ((х²-9у²)/ху) * ((ух)/(х²+6ху+9у²)) = (х²-(3у)²) / (х+3у)² = ((х-3у)(х+3у)) / (х+3у)² = (х-3у)/(х+3у)
(х²-ху+у²):((х³-х²у+ху²)/(х+у)) = ((х²-ху+у²)(х+у)) / ((х(х²-ху+у²)) = (х+у)/х
(х+у)/х = 7b/b = 7