6.41人参加运土劳动,有30根扁担,要安排多少人抬土,多少人挑土,可使扁担和人数相配?若设有x人挑土,则列出的方程是( )
| A. | 2x-(30-x)=41 | B. | $\frac{x}{2}$+(41-x)=30 | C. | x+$\frac{41-x}{2}$=30 | D. | 30-x=41-x |
5.下列变形中,属于移项变形的是( )
| A. | 由x-(2-3x)=5得x-2+3x=5 | B. | 由$\frac{x}{5}$=5得x=25 | ||
| C. | 由7x=6x-4得7x-6x=-4 | D. | 由5x=2得x=$\frac{2}{5}$ |
4.下列计算不正确的是( )
| A. | -$\frac{3}{2}$+$\frac{1}{2}$=-2 | B. | (-$\frac{1}{3}$)2=$\frac{1}{9}$ | C. | |-3|=3 | D. | -(-2)=2 |
2.
如图,在Rt△ABC中,∠C=90°,将△ABC绕点B顺时针旋转,得到△A′BC′,点C′在AB的延长线上,连接AA′,若∠AA′B=35°,则∠CAB的度数是( )
| A. | 10° | B. | 15° | C. | 20° | D. | 无法确定 |
20.
如图,已知矩形ABCD与矩形EFGO在平面直角坐标系中,点B的坐标为(-4,4),点F的坐标为(2,1),若矩形ABCD和矩形EFGO是位似图形,点P(点P在线段GC上)是位似中心,则点P的坐标为( )
| A. | (0,3) | B. | (0,2.5) | C. | (0,2) | D. | (0,1.5) |
19.
如图,在正方形ABCD中,AB=2$\sqrt{2}$,连接AC,以点C为圆心、AC长为半径画弧,点E在BC的延长线上,则阴影部分的面积为( )
0 286620 286628 286634 286638 286644 286646 286650 286656 286658 286664 286670 286674 286676 286680 286686 286688 286694 286698 286700 286704 286706 286710 286712 286714 286715 286716 286718 286719 286720 286722 286724 286728 286730 286734 286736 286740 286746 286748 286754 286758 286760 286764 286770 286776 286778 286784 286788 286790 286796 286800 286806 286814 366461
| A. | 6π-4 | B. | 8π-8 | C. | 10π-4 | D. | 12π-8 |