Question

已知x,y均為正數(shù),且x>y,
求證:2x+≥2y+3.

Answer 1

見解析

【證明】因為x>0,y>0,x-y>0,
2x+-2y=2(x-y)+
=(x-y)+(x-y)+
≥3=3,
所以2x+≥2y+3.