If x, y, and z are positive integers, is x-y odd?(1) x=z^2(2) y=(z-1)^2
举报
x-y=(2z-1)*1-->奇数
所以C
谢谢!!!
Smart answer.
I can elaborate it.
x-y=z^2 -z^2+2z-1
=>x-y =2z-1
We know any number multiplied by 2 is even. And if 1 is deducted from it that becomes odd.
So, x-y is odd.
Am I right??
发表回复
手机版|ChaseDream|GMT+8, 2025-6-11 16:14 京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
ChaseDream 论坛
© 2003-2025 ChaseDream.com. All Rights Reserved.