分析:(1)根據(jù)單項(xiàng)式系數(shù)、次數(shù)的定義來求解.單項(xiàng)式中數(shù)字因數(shù)叫做單項(xiàng)式的系數(shù),所有字母的指數(shù)和叫做這個(gè)單項(xiàng)式的次數(shù);
(2)根據(jù)多項(xiàng)式次數(shù)的定義求解.由于多項(xiàng)式的次數(shù)是“多項(xiàng)式中次數(shù)最高的項(xiàng)的次數(shù)”,據(jù)此可解此題.
解答:解:(1)代數(shù)式
-是6次單項(xiàng)式,系數(shù)為
-.
(2)多項(xiàng)式
3x2y-7x4y2-xy3+27是6次4項(xiàng)式,最高次項(xiàng)是-7x
4y
2.
故答案為:(1)6,-
;(2)6,4,-7x
4y
2.
點(diǎn)評(píng):本題考查了單項(xiàng)式系數(shù)、次數(shù)的定義及多項(xiàng)式的次數(shù)、項(xiàng)數(shù).確定單項(xiàng)式的系數(shù)和次數(shù)時(shí),把一個(gè)單項(xiàng)式分解成數(shù)字因數(shù)和字母因式的積,是找準(zhǔn)單項(xiàng)式的系數(shù)和次數(shù)的關(guān)鍵.