15.方程(m-2)x|m|-1-2=0是关于x的一元一次方程,则m的值为( )
| A. | -2 | B. | 2 | C. | -1 | D. | 2或-2 |
14.若a与2013互为相反数,则a的倒数为( )
| A. | -2013 | B. | 2013 | C. | $\frac{1}{2013}$ | D. | $-\frac{1}{2013}$ |
13.《孙子算经》中有一道题,原文是:“今有木,不知长短.引绳度之,余绳四尺五寸;屈绳量之,不足一尺.木长几何?”意思是:用一根绳子去量一根长木,绳子还剩余4.5尺;将绳子对折再量长木,长木还剩余1尺,问木长多少尺.设木长为x尺,绳子长为y尺,则下列符合题意的方程组是( )
| A. | $\left\{\begin{array}{l}{y=x+4.5}\\{\frac{1}{2}y=x+1}\end{array}\right.$ | B. | $\left\{\begin{array}{l}{y=x+4.5}\\{\frac{1}{2}y=x-1}\end{array}\right.$ | C. | $\left\{\begin{array}{l}{y=4.5-x}\\{\frac{1}{2}y=x+1}\end{array}\right.$ | D. | $\left\{\begin{array}{l}{y=x-4.5}\\{\frac{1}{2}y=x-1}\end{array}\right.$ |
12.下列说法错误的是( )
0 284610 284618 284624 284628 284634 284636 284640 284646 284648 284654 284660 284664 284666 284670 284676 284678 284684 284688 284690 284694 284696 284700 284702 284704 284705 284706 284708 284709 284710 284712 284714 284718 284720 284724 284726 284730 284736 284738 284744 284748 284750 284754 284760 284766 284768 284774 284778 284780 284786 284790 284796 284804 366461
| A. | 1的平方根是1 | B. | 0的平方根是0 | ||
| C. | 1的算术平方根是1 | D. | -1的立方根是-1 |