Question

11．單項(xiàng)式-$\frac{3{a}^{2}b}{5}$的系數(shù)和次數(shù)分別是（　�。�

• A． $\frac{3}{5}$和2
• B． $\frac{3}{5}$和3
• C． -$\frac{3}{5}$和2
• D． -$\frac{3}{5}$和3

Answer 1

分析 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)和叫做這個單項(xiàng)式的次數(shù)．

解答 解：根據(jù)單項(xiàng)式系數(shù)、次數(shù)的定義可知，單項(xiàng)式-$\frac{3{a}^{2}b}{5}$的系數(shù)是：-$\frac{3}{5}$，次數(shù)是：2+1=3．
故選：D．

點(diǎn)評 此題主要考查了單項(xiàng)式，確定單項(xiàng)式的系數(shù)和次數(shù)時，把一個單項(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．