14.若△ABC是边长为1的等边三角形,且$\overrightarrow{AD}$=2$\overrightarrow{DB}$,2$\overrightarrow{AE}$=$\overrightarrow{EC}$,则$\overrightarrow{CD}$$•\overrightarrow{BE}$=( )
| A. | -$\frac{1}{9}$ | B. | -$\frac{2}{9}$ | C. | -$\frac{1}{3}$ | D. | -$\frac{7}{18}$ |
9.若实数x,y满足{x≥0y≥04x+3y≤12,则z=y+12x-2的取值范围是( )
0 234902 234910 234916 234920 234926 234928 234932 234938 234940 234946 234952 234956 234958 234962 234968 234970 234976 234980 234982 234986 234988 234992 234994 234996 234997 234998 235000 235001 235002 235004 235006 235010 235012 235016 235018 235022 235028 235030 235036 235040 235042 235046 235052 235058 235060 235066 235070 235072 235078 235082 235088 235096 266669
| A. | [-12,14] | B. | [-52,14] | C. | (-∞,-12]∪[14,+∞) | D. | (-∞,-52]∪[14,+∞) |