... ❧➔♠ ♥❤÷ s❛✉✿ (2x2 y).(9xy ) = (2.9)(x2 y)(xy ) = 18( x2 x)(yy ) = 18x3 y ✶✸ ❑❤â❛ ❧✉➟♥ tèt ♥❣❤✐➺♣ ✣↕✐ ❤å❝ ❚❛ ♥â✐ ✤ì♥ t❤ù❝ ❍♦➔♥❣ ❚❤à ❑❤→♥❤ ▲✐♥❤ 18x3 y ❧➔ t➼❝❤ ❝õ❛ ❤❛✐ ✤ì♥ t❤ù❝ 2x2 y ✈➔ 9xy ✳ ✯ ◆❤➙♥... +15x2 +11x −3 x2 − 4x − 2x4 −8x3 −6x2 −5x3 +21x2 +11x −3 −5x3 +20x2 +15x x2 2x2 − 5x −4x −3 ❚❤ü❝ ❤✐➺♥ t÷ì♥❣ tü ♥❤÷ tr➯♥✱ t❛ ✤÷đ❝✿ 2x4 −13x3 +15x2 +11x −3 x2 − 4x − 2x4 −8x3 −6x2 2x2 − 5x + −5x3 +21x2... ♥❣♦➦❝ ✭❦➸ ❝↔ ❞➜✉ ❝õ❛ ❝❤ó♥❣✮✳ ❱➼ ❞ư✿ P❤➙♥ t➼❝❤ ✤❛ t❤ù❝ s❛✉ ❜➡♥❣ ♣❤÷ì♥❣ ♣❤→♣ ✤➦t ♥❤➙♥ tû ❝❤✉♥❣✳ 28x2 y − 21xy + 14x2 y = 7xy(4xy − 3y + 2x) ✰✮ ❉ò♥❣ ❤➡♥❣ ✤➥♥❣ t❤ù❝ ❱➟♥ ❞ư♥❣ ❝→❝ ❤➡♥❣ ✤➥♥❣ t❤ù❝ ✤→♥❣