10.下列因式分解错误的是( )
| A. | 8a-4b+12=4(2a-b+3) | B. | 4a2+4a+1=(2a+1)2 | ||
| C. | m2-n2=(m+n)(m-n) | D. | x2+y2=(x+y)2 |
9.二元一次方程组$\left\{\begin{array}{l}{x+y=5}\\{x-y=1}\end{array}\right.$的解是( )
| A. | $\left\{\begin{array}{l}{x=3}\\{y=2}\end{array}\right.$ | B. | $\left\{\begin{array}{l}{x=6}\\{y=-1}\end{array}\right.$ | C. | $\left\{\begin{array}{l}{x=4}\\{y=1}\end{array}\right.$ | D. | $\left\{\begin{array}{l}{x=1}\\{y=0}\end{array}\right.$ |
8.下列四个命题中是假命题的是( )
| A. | 若a>b,则a-c>b-c | B. | 同位角一定相等 | ||
| C. | 若∠1+∠2=180°,则∠1与∠2互为补角 | D. | 平行于同一条直线的两条直线平行 |
7.下列计算错误的是( )
| A. | (-4xy2)3=-12x3y6 | B. | 2a3+a3=3a3 | C. | m4•m2=m6 | D. | 2-2=$\frac{1}{4}$ |
6.下列四个选项中,不是多边形内角和的是( )
0 306817 306825 306831 306835 306841 306843 306847 306853 306855 306861 306867 306871 306873 306877 306883 306885 306891 306895 306897 306901 306903 306907 306909 306911 306912 306913 306915 306916 306917 306919 306921 306925 306927 306931 306933 306937 306943 306945 306951 306955 306957 306961 306967 306973 306975 306981 306985 306987 306993 306997 307003 307011 366461
| A. | 360° | B. | 540° | C. | 600° | D. | 2160° |