7.下列说法正确的是( )
| A. | 由5m=6m+2可得m=2 | |
| B. | 方程的解就是方程中未知数所取的值 | |
| C. | 方程2x-1=3的解是x=2 | |
| D. | 方程x=-x没有解 |
6.下列二次函数的图象中经过原点的是( )
| A. | y=x2+1 | B. | y=2x2+5x | C. | y=(x-2)2 | D. | y=x2+2x-3 |
5.平面直角坐标系内一点P(-5,1)关于原点对称的点的坐标是( )
0 290432 290440 290446 290450 290456 290458 290462 290468 290470 290476 290482 290486 290488 290492 290498 290500 290506 290510 290512 290516 290518 290522 290524 290526 290527 290528 290530 290531 290532 290534 290536 290540 290542 290546 290548 290552 290558 290560 290566 290570 290572 290576 290582 290588 290590 290596 290600 290602 290608 290612 290618 290626 366461
| A. | (5,-1) | B. | (5,-1) | C. | (-5,-1) | D. | (5,1) |