9.已知|x-1|+(2y+1)2=0,且2x-ky=4,则k的值( )
| A. | 1 | B. | 3 | C. | 4 | D. | 5 |
8.已知x=$\frac{\sqrt{32}+\sqrt{3}}{\sqrt{2}}$,若x在两个相邻整数之间,则这两个整数是( )
| A. | 3和4 | B. | 4和5 | C. | 5和6 | D. | 6和7 |
7.下列运算正确的是( )
| A. | $\sqrt{9}$=±3 | B. | (m2)3=m6 | C. | a2•a3=a6 | D. | (x+y)2=x2+y2 |
3.下列计算正确的是( )
0 284968 284976 284982 284986 284992 284994 284998 285004 285006 285012 285018 285022 285024 285028 285034 285036 285042 285046 285048 285052 285054 285058 285060 285062 285063 285064 285066 285067 285068 285070 285072 285076 285078 285082 285084 285088 285094 285096 285102 285106 285108 285112 285118 285124 285126 285132 285136 285138 285144 285148 285154 285162 366461
| A. | 3a+2a=6a | B. | a3•a4=a12 | C. | a10÷a2=a5 | D. | (-4a4b)2=16a8b2 |