5.下列是电视台的台标,属于中心对称图形的是( )
| A. | B. | C. | D. |
4.已知(x+y)2=9,且(x-y)2=5,则xy的值是( )
| A. | 14 | B. | 4 | C. | 2 | D. | 1 |
3.若分式$\frac{{x}^{2}-1}{x+1}$=0,则x的值是( )
| A. | -1 | B. | 0 | C. | 1 | D. | -2 |
2.
如图,AB=BD,BC=BE,要使△ABE≌△DBC,需添加条件( )
| A. | ∠ABE=∠DBC | B. | ∠C=∠E | C. | ∠D=∠E | D. | ∠A=∠D |
1.正十边形每个内角的度数是多少( )
| A. | 180° | B. | 144° | C. | 150° | D. | 120° |
20.已知am=3,an=4,则am+n的值为( )
| A. | 12 | B. | 7 | C. | $\frac{3}{4}$ | D. | $\frac{4}{3}$ |
19.使分式$\frac{x+1}{x-2}$有意义的x的取值范围是( )
0 294829 294837 294843 294847 294853 294855 294859 294865 294867 294873 294879 294883 294885 294889 294895 294897 294903 294907 294909 294913 294915 294919 294921 294923 294924 294925 294927 294928 294929 294931 294933 294937 294939 294943 294945 294949 294955 294957 294963 294967 294969 294973 294979 294985 294987 294993 294997 294999 295005 295009 295015 295023 366461
| A. | x≠0 | B. | x≠-1 | C. | x≠1 | D. | x≠2 |