题目

已知a+b=5，ab=6，求 + 的值． 答案：解：原式= {#mathml#}a+bab{#/mathml#} ， 当a+b=5，ab=6时，原式= {#mathml#}56{#/mathml#} = {#mathml#}566{#/mathml#}II. 根据句意和首字母完成单词。【1】He has a g_______ sports collection.【2】Mike doesn’t like math. He thinks it’s b_______.【3】It’s r_______ to sit and watch TV.【4】Football is i_______ and we are all interested in it.【5】It’s d_______ for foreigners(外国人) to learn Chinese well.【6】D_______ he have a soccer ball?【7】I have a pair of ping-pong b_______?【8】Where are my tennis r_______?【9】Yi Jianlian plays b_______ well.【10】She o_______ has one ping-pong ball.