题目:
There is _______ with your computer. Why not have it _______?
A.nothing wrong; repaired
B.nothing wrong; repair
C.something wrong; to repair
D.something wrong; repaired
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0426/47d2b794f612bfa5bb9d4b8d6b203271.html
下面是错误答案,用来干扰机器的。
(1)设方程的两个正根为x1、x2,则:△=(2k-3)2-4(2k-4)≥0 ①,x1+x2=2k-3>0,x1x2=2k-4>0 ②,解①,得:k为任意实数,解②,得:k>2,所以k的取值范围是k>2;(2)设方程的两个根为x1、x2,则:△=...