14.已知$\frac{a}{b}$=$\frac{1}{3}$,则$\frac{b-a}{b}$的值为( )
| A. | $\frac{2}{3}$ | B. | $\frac{3}{2}$ | C. | $\frac{1}{2}$ | D. | 2 |
13.函数y=$\frac{k}{x}$的图象经过点(-4,6),则下列各点中在y=$\frac{k}{x}$图象上的是( )
| A. | (3,8) | B. | (3,-8) | C. | (-8,-3) | D. | (-4,-6) |
12.
如图所示的几何体的主视图是( )
| A. | B. | C. | D. |
10.
如图,双曲线y=-$\frac{2}{x}$与y=$\frac{6}{x}$分别过矩形ABCO上的A、D两点,OD=2CD,矩形ABCO面积为18$\sqrt{3}$,则OC的长为( )
| A. | 6 | B. | $6\sqrt{3}$ | C. | 9 | D. | $9\sqrt{3}$ |
6.若k为正整数,则2•(-2)2k+(-2)2k+1等于( )
0 293045 293053 293059 293063 293069 293071 293075 293081 293083 293089 293095 293099 293101 293105 293111 293113 293119 293123 293125 293129 293131 293135 293137 293139 293140 293141 293143 293144 293145 293147 293149 293153 293155 293159 293161 293165 293171 293173 293179 293183 293185 293189 293195 293201 293203 293209 293213 293215 293221 293225 293231 293239 366461
| A. | 0 | B. | 22k+1 | C. | -22k+1 | D. | 22k+2 |