Question

蘋(píng)果樹(shù)有a棵，梨樹(shù)是蘋(píng)果樹(shù)的3倍，蘋(píng)果樹(shù)和梨樹(shù)一共有________棵，梨樹(shù)比蘋(píng)果樹(shù)多________棵．

Answer 1

4a    2a
分析：（1）根據(jù)“梨樹(shù)是蘋(píng)果樹(shù)的3倍”得：梨樹(shù)的棵數(shù)=蘋(píng)果樹(shù)的棵數(shù)×3，即3a棵，再加上蘋(píng)果樹(shù)的棵數(shù)a棵即可；
（2）用梨樹(shù)的棵數(shù)-蘋(píng)果樹(shù)的棵數(shù)即可．
解答：（1）蘋(píng)果樹(shù)和梨樹(shù)共有：a+3a=4a（棵）．
答：蘋(píng)果樹(shù)和梨樹(shù)一共有4a棵．
（2）3a-a=2a（棵）．
答：梨樹(shù)比蘋(píng)果樹(shù)多2a棵．
故答案為：4a；2a．
點(diǎn)評(píng)：解答此題的關(guān)鍵是，根據(jù)已知條件，把未知的數(shù)用字母正確的表示出來(lái)，再結(jié)合所求的問(wèn)題，即可得出答案．