12.
实数a,b在数轴上的对应点的位置如图所示,则正确的结论是( )
| A. | a>0 | B. | a>b | C. | |a|>|b| | D. | a>-b |
11.在建的北京新国际机场预计2025年旅客吞吐量将达到72 000 000人次.将72 000 000用科学记数法表示应为( )
| A. | 7.2×106 | B. | 72×106 | C. | 7.2×107 | D. | 0.72×108 |
9.
如图所示是婴儿车的平面示意图,其中AB∥CD,∠1=121°,∠3=42°,那么∠2的度数为( )
| A. | 79° | B. | 89° | C. | 59° | D. | 91° |
8.二元一次方程组$\left\{\begin{array}{l}{x+y=7}\\{3x-y=5}\end{array}\right.$的解是( )
| A. | $\left\{\begin{array}{l}{x=4}\\{y=3}\end{array}\right.$ | B. | $\left\{\begin{array}{l}{x=5}\\{y=2}\end{array}\right.$ | C. | $\left\{\begin{array}{l}{x=3}\\{y=4}\end{array}\right.$ | D. | $\left\{\begin{array}{l}{x=-2}\\{y=9}\end{array}\right.$ |
7.下列把多项式分解因式正确的是( )
| A. | -ma-m=-m(a-1) | B. | x2-y2=(x-y)2 | C. | a2+3a+9=(a+3)2 | D. | 2x2-2=2(x+1)(x-1) |
6.实数$\sqrt{16}$的平方根是( )
| A. | ±4 | B. | 4 | C. | 2 | D. | ±2 |
5.2016年普宁市重点项目累计完成投资187.35亿元,将187.35亿用科学记数法表示为( )
| A. | 187.35×108 | B. | 1.8735×109 | C. | 1.8735×1010 | D. | 1.8735×1011 |
4.-2017的绝对值是( )
| A. | -2017 | B. | 2017 | C. | -$\frac{1}{2017}$ | D. | $\frac{1}{2017}$ |
3.若等腰三角形的两边长为3和5,则该等腰三角形的周长为( )
0 295662 295670 295676 295680 295686 295688 295692 295698 295700 295706 295712 295716 295718 295722 295728 295730 295736 295740 295742 295746 295748 295752 295754 295756 295757 295758 295760 295761 295762 295764 295766 295770 295772 295776 295778 295782 295788 295790 295796 295800 295802 295806 295812 295818 295820 295826 295830 295832 295838 295842 295848 295856 366461
| A. | 11 | B. | 13 | C. | 11或13 | D. | 12 |