Question

多項(xiàng)式8xy-5x²+4x³y+1是________次________項(xiàng)式；按字母x的降冪排列是________．

Answer 1

四    四    4x³y-5x²+8xy+1
分析：多項(xiàng)式的次數(shù)是多項(xiàng)式中最高次項(xiàng)的次數(shù)，有幾項(xiàng)就是幾項(xiàng)式．
解答：8xy-5x²+4x³y+1是四次四項(xiàng)式；
按字母x的降冪排列是4x³y-5x²+8xy+1．
故答案為：四，四；4x³y-5x²+8xy+1．
點(diǎn)評(píng)：本題考查了多項(xiàng)式的定義，解題的關(guān)鍵是弄清多項(xiàng)式次數(shù)是多項(xiàng)式中次數(shù)最高的項(xiàng)的次數(shù)．熟練掌握幾次幾項(xiàng)式的概念．