Question

單項(xiàng)式-2²x³y²的系數(shù)為_(kāi)_______，次數(shù)為_(kāi)_______；-的系數(shù)為_(kāi)_______，次數(shù)為_(kāi)_______；mn的系數(shù)為_(kāi)_______，次數(shù)為_(kāi)_______．

Answer 1

-4    5    -    3    1    2
分析：根據(jù)單項(xiàng)式系數(shù)、次數(shù)的定義來(lái)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)．
解答：根據(jù)單項(xiàng)式定義得：?jiǎn)雾?xiàng)式-2²x³y²的系數(shù)為-4，次數(shù)為5；-的系數(shù)為-，次數(shù)為3；mn的系數(shù)為1，次數(shù)為2．
點(diǎn)評(píng)：本題考查了單項(xiàng)式定義．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．注意π是數(shù)字，不是字母；系數(shù)是1或-1時(shí)，不能忽略．