7.
如图,六边形是由甲、乙两个矩形和丙、丁两个等腰三角形所组成的,其中甲、乙的面积的和等于丙、丁的面积的和.若丙的腰长为2,且丁的面积比丙的小,则丁的腰长为( )
| A. | $\frac{1}{2}$ | B. | $\frac{3}{5}$ | C. | 2-$\sqrt{3}$ | D. | 4-2$\sqrt{3}$ |
6.甲比乙大15岁,5年前甲的年龄是乙的年龄的两倍,则现在乙的年龄为( )
| A. | 35 | B. | 30 | C. | 20 | D. | 15 |
2.
已知:如图,DE∥BC,S△ADE=3,S△EBC=18,则S△BDE为( )
| A. | 2 | B. | 4 | C. | 6 | D. | 8 |
1.下列正比例函数中,y的值随着x值的增大而减小的是( )
0 295610 295618 295624 295628 295634 295636 295640 295646 295648 295654 295660 295664 295666 295670 295676 295678 295684 295688 295690 295694 295696 295700 295702 295704 295705 295706 295708 295709 295710 295712 295714 295718 295720 295724 295726 295730 295736 295738 295744 295748 295750 295754 295760 295766 295768 295774 295778 295780 295786 295790 295796 295804 366461
| A. | $y=(\sqrt{2}-\sqrt{3})x$ | B. | $y=\frac{1}{5}x$ | C. | y=2x | D. | y=0.2x |