1.下列计算正确的是( )
| A. | -$\sqrt{(-3)^{2}}$=-3 | B. | (-$\sqrt{8}$)2=64 | C. | $\sqrt{(-25)^{2}}$=±25 | D. | $\sqrt{9\frac{1}{16}}$=3$\frac{1}{4}$ |
13.下列式子成立的是( )
| A. | 2x-5=-(5-2x) | B. | 7a+3=7(a+3) | C. | -a-b=-(a-b) | D. | 2x-5=-(2x-5) |
12.下列等式正确的是( )
0 285851 285859 285865 285869 285875 285877 285881 285887 285889 285895 285901 285905 285907 285911 285917 285919 285925 285929 285931 285935 285937 285941 285943 285945 285946 285947 285949 285950 285951 285953 285955 285959 285961 285965 285967 285971 285977 285979 285985 285989 285991 285995 286001 286007 286009 286015 286019 286021 286027 286031 286037 286045 366461
| A. | 43=34 | B. | -53=(-5)3 | C. | -42=(-4)2 | D. | ${(-\frac{2}{3})^2}={(-\frac{3}{2})^2}$ |