17.当x=2时,代数式ax3+bx+1的值为6,那么当x=-2时,这个代数式的值是( )
| A. | 1 | B. | -4 | C. | 6 | D. | -5 |
13.在实数$\sqrt{5}$,$\frac{π}{2}$,-$\frac{333}{222}$,$\sqrt{36}$,3.020020002…(每相邻两个2之间0的个数逐渐多1)中,属于无理数的共有( )
| A. | 2个 | B. | 3个 | C. | 4个 | D. | 5个 |
12.
已知:如图,直线a∥b,AC⊥AB于A,AC交直线b于点C,∠1=46°,则∠2的度数是( )
| A. | 50° | B. | 45° | C. | 44° | D. | 30° |
11.下列方程组中,是二元一次方程组的是( )
| A. | $\left\{\begin{array}{l}{\frac{1}{x}+y=4}\\{x-y=1}\end{array}\right.$ | B. | $\left\{\begin{array}{l}{4x+3y=6}\\{2y+z=4}\end{array}\right.$ | ||
| C. | $\left\{\begin{array}{l}{x+y=4}\\{x-y=1}\end{array}\right.$ | D. | $\left\{\begin{array}{l}{x+y=5}\\{{x}^{2}+{y}^{2}=13}\end{array}\right.$ |
10.下列计算中,错误的是( )
0 287325 287333 287339 287343 287349 287351 287355 287361 287363 287369 287375 287379 287381 287385 287391 287393 287399 287403 287405 287409 287411 287415 287417 287419 287420 287421 287423 287424 287425 287427 287429 287433 287435 287439 287441 287445 287451 287453 287459 287463 287465 287469 287475 287481 287483 287489 287493 287495 287501 287505 287511 287519 366461
| A. | $\sqrt{2}$+$\sqrt{2}$=2$\sqrt{2}$ | B. | $\sqrt{2}$-($\sqrt{3}$+$\sqrt{2}$)=-$\sqrt{3}$ | C. | |$\sqrt{2}$-$\sqrt{3}$|+2$\sqrt{2}$=$\sqrt{3}$+$\sqrt{2}$ | D. | 2$\sqrt{3}$-3$\sqrt{3}$=-1 |