16.下列分解因式中,正确的是( )
| A. | 2x2y-xy2+xy=xy(2x-y) | B. | (x+4y)2-(2x)2=(x+4y+2x)(x+4y-2x) | ||
| C. | x3-2x2+x=x(x-1)2 | D. | 1-4x2y2=(1+4xy)(1-4xy) |
15.下列等式成立的是( )
| A. | $\frac{a}{b}$=$\frac{{a}^{2}}{{b}^{2}}$ | B. | $\frac{a}{b}$=$\frac{a+c}{b+c}$ | C. | $\frac{a}{b}$=$\frac{a-c}{b-c}$ | D. | $\frac{a}{b}$=$\frac{ma}{mb}$(m≠0) |
14.下列命题中是真命题的是( )
| A. | 三角形的外角大于它的内角 | |
| B. | 两条边及一个角对应相等的两三角形全等 | |
| C. | 同位角的平分线互相平行 | |
| D. | 位以图形一定是相似图形 |
13.若使分式$\frac{x}{x+3}$有意义,则x的取值范围是( )
0 309734 309742 309748 309752 309758 309760 309764 309770 309772 309778 309784 309788 309790 309794 309800 309802 309808 309812 309814 309818 309820 309824 309826 309828 309829 309830 309832 309833 309834 309836 309838 309842 309844 309848 309850 309854 309860 309862 309868 309872 309874 309878 309884 309890 309892 309898 309902 309904 309910 309914 309920 309928 366461
| A. | x≠3 | B. | x≠-3 | C. | x≠0 | D. | x>-3 |