若M(2x-y2)=y4-4x2,则代数式M应为(  ) A.-(2x+y2) B.-y2+2x C.2x+y2 D.2x-y2

问题描述:

若M(2x-y2)=y4-4x2,则代数式M应为(  )
A. -(2x+y2
B. -y2+2x
C. 2x+y2
D. 2x-y2

∵-(2x+y2)(2x-y2)=y4-4x2
∴M=-(2x+y2).
故选A.