11.
如图,已知AM:MD=4:1,BD:DC=2:3,则AE:EC=( )
| A. | 4:3 | B. | 3:2 | C. | 7:3 | D. | 8:5 |
4.下列式子成立的是( )
0 279617 279625 279631 279635 279641 279643 279647 279653 279655 279661 279667 279671 279673 279677 279683 279685 279691 279695 279697 279701 279703 279707 279709 279711 279712 279713 279715 279716 279717 279719 279721 279725 279727 279731 279733 279737 279743 279745 279751 279755 279757 279761 279767 279773 279775 279781 279785 279787 279793 279797 279803 279811 366461
| A. | $\frac{x^6}{x^2}={x^3}$ | B. | $\frac{a-b}{a-b}=0$ | C. | ${({\frac{m}{2n}})^2}=\frac{m^2}{{4{n^2}}}$ | D. | $\frac{{{a^2}+{b^2}}}{a+b}=a+b$ |