题目

方程的较大根为，方程 的较小根为，求的值. 答案：解：将方程分解因式，得， ∴ 或，∴ ，∴ 较大根为1，即. 将方程变形，得 ， ∴ ，∴ ， ∴ ，∴ 或， ∴，，∴ 较小根为-1，即，∴ .用方框中所给单词的适当形式填空，使短文通顺、正确、连贯(每个单词限用一次)。 use  happy   healthy   fun   exercise   fly   hard   swim   listen   many The summer vacation is over. It’s true that time always61        fast. During the vacation, the weather was hot and I could not do much work, but I lived 62        . As the afternoon was hot. I did my work in the morning. I 63       to get up at 6:30 and take a walk in the garden for half an hour. After breakfast, I began reading English and Chinese and did some 64        in math, It took me three hours or65        . I worked quite 66and made good progress. I spent the afternoon outside. I went to swim and it was 67        . I would not go home until it was about five or six o’clock. Sometimes a friend of mine would come to see me and we would spend some hours 68        to music. In this way I spent my vacation slowly. And I not only studied well but also became a good 69          . now I am in good 70         and high spirits.