4.
如图,经过点B(-2,0)的直线y=kx+b与直线y=kx+b相交于点A(-1,-2),则不等式4x+2<kx+b<0的解集为( )
| A. | -2<x<-1 | B. | -2$<x<-\frac{1}{2}$ | C. | -1$<x<-\frac{1}{2}$ | D. | -$\frac{1}{2}<x<0$ |
1.
如图,在△ABC中,AB=AC,∠A=36°,BD平分∠ABC交AC于点D,过点D作DE∥AB,交BC于点E,下列结论中错误的是( )
| A. | DE平分∠BDC | B. | △ABC∽△BDC∽△DEC | C. | $\frac{AD}{AB}$=$\frac{\sqrt{5}-1}{2}$ | D. | $\frac{{S}_{△BCD}}{{S}_{△ABD}}$=$\frac{1}{2}$ |
18.已知二元一次方程组$\left\{\begin{array}{l}{2x-y=3}\\{3x-4y=3}\end{array}\right.$,则x-y等于( )
| A. | 1.1 | B. | 1.2 | C. | 1.3 | D. | 1.4 |
17.下列运算中,正确的是( )
| A. | a2+a=2a3 | B. | a2•a3=a5 | C. | (a2)3=a5 | D. | (ab2)3=a3b2 |
16.把多项式x2-x提取公因式x后,余下的部分是( )
| A. | x | B. | x-1 | C. | x+1 | D. | x2 |
15.对分式$\frac{1}{2({a}^{2}-9)}$,$\frac{3}{4({a}^{2}+6a+9)}$通分时,最简公分母是( )
0 284737 284745 284751 284755 284761 284763 284767 284773 284775 284781 284787 284791 284793 284797 284803 284805 284811 284815 284817 284821 284823 284827 284829 284831 284832 284833 284835 284836 284837 284839 284841 284845 284847 284851 284853 284857 284863 284865 284871 284875 284877 284881 284887 284893 284895 284901 284905 284907 284913 284917 284923 284931 366461
| A. | 4(a-3)(a+3)2 | B. | 4(a2-9)(a2+6a+9) | C. | 8(a2-9)(a2+6a+9) | D. | 4(a-3)2(a+3)2 |