若n是正整数,有理数x、y满足x+1y=0,则一定成立的是( ) A.x2n+1+(1y)n=0 B.x2n+1+(1y)2n+1=0 C.x2n+(1y)2n=0 D.xn+(1y)2n=0
问题描述:
若n是正整数,有理数x、y满足x+
=0,则一定成立的是( )1 y
A. x2n+1+(
)n=01 y
B. x2n+1+(
)2n+1=01 y
C. x2n+(
)2n=01 y
D. xn+(
)2n=0 1 y
答
∵有理数x、y满足x+
=0,1 y
∴x与
互为相反数.1 y
∴x2n+1+(
)2n+1=0,x2n+(1 y
)2n=2x2n或2×(1 y
)2n;1 y
故选B.