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