8.下列计算正确的是( )
0 283521 283529 283535 283539 283545 283547 283551 283557 283559 283565 283571 283575 283577 283581 283587 283589 283595 283599 283601 283605 283607 283611 283613 283615 283616 283617 283619 283620 283621 283623 283625 283629 283631 283635 283637 283641 283647 283649 283655 283659 283661 283665 283671 283677 283679 283685 283689 283691 283697 283701 283707 283715 366461
| A. | -$\frac{x}{y}$÷2y=-$\frac{x}{2}$ | B. | a2b•$\frac{a}{2b}$=$\frac{{a}^{3}}{2}$ | C. | (a2-b2)•$\frac{1}{b-a}$=a+b | D. | m3n2÷$\frac{{n}^{2}}{m}$•m=m3 |