20.
如图,在Rt△ABC中,∠BAC=90°,∠ACB=45°,点D是AB中点,AF⊥CD于点H,交BC于点F,BE∥AC交AF的延长线于点E,给出下列结论:①∠BAE=∠ACD,②△ADC≌△BEA,③AC=AF,④∠BDE=∠EDC,⑤BC⊥DE.上述结论正确的序号是( )
| A. | ①②⑤ | B. | ②④⑤ | C. | ①②④ | D. | ①②③ |
19.
如图:在平面直角坐标系中,点A(0,6),且∠AOB=∠BAO=45°,则点B的坐标为( )
| A. | (6,3) | B. | (2,3) | C. | (6,6) | D. | (3,3) |
18.化简x3•(-x)2的结果正确的是( )
| A. | -x6 | B. | x6 | C. | x5 | D. | -x5 |
12.今年国庆长假期间,涪洋镇“家家福”超市某商品按标价打八折销售,小玲购了一件该商品,付款56元,则该项商品的标价为( )元.
0 278926 278934 278940 278944 278950 278952 278956 278962 278964 278970 278976 278980 278982 278986 278992 278994 279000 279004 279006 279010 279012 279016 279018 279020 279021 279022 279024 279025 279026 279028 279030 279034 279036 279040 279042 279046 279052 279054 279060 279064 279066 279070 279076 279082 279084 279090 279094 279096 279102 279106 279112 279120 366461
| A. | 56 | B. | 68 | C. | 70 | D. | 72 |