5.
如图,在△ABC中,∠CAB=70°,将△ABC在平面内绕点A旋转到△AB′C′的位置,使CC′∥AB,则旋转角的度数为( )
| A. | 35° | B. | 40° | C. | 50° | D. | 70° |
4.在△ABC中,AB=AC=2,D为BC的中点,∠C=30°,则AD的长为( )
| A. | $\sqrt{3}$ | B. | $\sqrt{2}$ | C. | 1 | D. | 2 |
3.平面直角坐标系中,点A(0,2)平移后对应的点为A′(2,1),按同样的规律平移,则点A′(2,1)平移后的坐标为( )
| A. | (4,0) | B. | (2,0) | C. | (4,2) | D. | (1,2) |
1.已知a、b为任意实数,a>b,则下列变形一定正确的是( )
| A. | a-1>b-1 | B. | -a>-b | C. | |a|>|b| | D. | -$\frac{a}{2}$>-$\frac{b}{2}$ |
19.若关于x,y的方程组$\left\{\begin{array}{l}{x+2y=3m+1}\\{x-y=-5}\end{array}\right.$的解满足x+y=-3,则m的值为( )
| A. | -2 | B. | 2 | C. | -1 | D. | 1 |
18.若-63a3b4与81ax+1bx+y是同类项,则x、y的值为( )
| A. | $\left\{\begin{array}{l}{x=1}\\{y=3}\end{array}\right.$ | B. | $\left\{\begin{array}{l}{x=2}\\{y=-2}\end{array}\right.$ | C. | $\left\{\begin{array}{l}{x=1}\\{y=2}\end{array}\right.$ | D. | $\left\{\begin{array}{l}{x=2}\\{y=2}\end{array}\right.$ |
17.下列方程变形属于移项的是( )
0 294702 294710 294716 294720 294726 294728 294732 294738 294740 294746 294752 294756 294758 294762 294768 294770 294776 294780 294782 294786 294788 294792 294794 294796 294797 294798 294800 294801 294802 294804 294806 294810 294812 294816 294818 294822 294828 294830 294836 294840 294842 294846 294852 294858 294860 294866 294870 294872 294878 294882 294888 294896 366461
| A. | 由-2y-5=-1+y,得-2y-y=5-1 | B. | 由-3x=-6,得x=2 | ||
| C. | 由$\frac{1}{5}$y=2,得y=10 | D. | 由-2(1-2x)+3=0,得-2+4x+3=0 |