代數(shù)式-xy2系數(shù)是________,次數(shù)是________.
-1 3
分析:根據(jù)單項式系數(shù)、次數(shù)的定義來求解.單項式中數(shù)字因數(shù)叫做單項式的系數(shù),所有字母的指數(shù)和叫做這個單項式的次數(shù).
解答:根據(jù)單項式系數(shù)、次數(shù)的定義,代數(shù)式-xy2的數(shù)字因數(shù)-1即系數(shù),所有字母的指數(shù)和是1+2=3,故次數(shù)是3.
點評:確定單項式的系數(shù)和次數(shù)時,把一個單項式分解成數(shù)字因數(shù)和字母因式的積,是找準(zhǔn)單項式的系數(shù)和次數(shù)的關(guān)鍵.