16.等腰三角形的周长为9,一边长为4,则腰长为( )
| A. | 5 | B. | 4 | C. | 2.5 | D. | 2.5或4 |
15.
如图,∠BAC=90°,AD⊥BC,则图中互余的角有( )
| A. | 2对 | B. | 3对 | C. | 4对 | D. | 5对 |
14.如果x=0是关于x的方程3x-2a=4的解,则a的值是( )
| A. | 2 | B. | -2 | C. | $\frac{4}{3}$ | D. | -$\frac{4}{3}$ |
13.下列四个变形过程中错误的是( )
| A. | 若$\frac{4}{5}$($\frac{5}{4}$x-10)=8,则x-8=8 | B. | 若1-$\frac{1-x}{5}$=x,则5-1+X=5x | ||
| C. | 若-$\frac{1}{2}$(3x+6)+4x=1,则-$\frac{3}{2}$x+3+4x=1 | D. | 若3x-5y=-3,则-5y+3=-3x |
12.下列式子中是一元一次方程的是( )
| A. | $\frac{1}{x}$-2=5 | B. | 2x-3 | C. | x=y | D. | 3x=0 |
9.
某地需要开辟一条隧道,隧道AB的长度无法直接测量.如图所示,在地面上取一点C,使C到A、B两点均可直接到达,测量找到AC和BC的中点D、E,测得DE的长为1100m,则隧道AB的长度为( )
0 294501 294509 294515 294519 294525 294527 294531 294537 294539 294545 294551 294555 294557 294561 294567 294569 294575 294579 294581 294585 294587 294591 294593 294595 294596 294597 294599 294600 294601 294603 294605 294609 294611 294615 294617 294621 294627 294629 294635 294639 294641 294645 294651 294657 294659 294665 294669 294671 294677 294681 294687 294695 366461
| A. | 3300 m | B. | 2200 m | C. | 1100 m | D. | 550 m |