Giải: Đặt a=x+2011;b=y+2011;c=z+2011 (a;b;c>=0)thay vào hệ. suy ra a+b+1+c+2=c+a+1+b+2<=>c+2−c=(a+1−a)+(b+2−b+1)<=>c+2−c+1+c+1−c=VP<=>1c+1+c+2+1c+1+c=1a+a+1+1b+1+b+2" role="presentation" style="display: inline; font-size: 14px; word-spacing: 0px; color: rgb(40, 40, 40); font-family: helvetica, arial, sans-serif; position: relative; background-color: rgb(255, 255, 255);">a√+b+1−−−−√+c+2−−−−√=c√+a+1−−−−√+b+2−−−−√<=>c+2−−−−√−c√=(a+1−−−−√−a√)+(b+2−−−−√−b+1−−−−√)<=>c+2−−−−√−c+1−−−−√+c+1−−−−√−c√=VP<=>1c+1−−−−√+c+2−−−−√+1c+1−−−−√+c√=1a√+a+1−−−−√+1b+1−−−−√+b+2−−−−√a+b+1+c+2=c+a+1+b+2<=>c+2−c=(a+1−a)+(b+2−b+1)<=>c+2−c+1+c+1−c=VP<=>1c+1+c+2+1c+1+c=1a+a+1+1b+1+b+2 (1)Với c≥a;a≥b" role="presentation" style="display: inline; font-size: 14px; word-spacing: 0px; color: rgb(40, 40, 40); font-family: helvetica, arial, sans-serif; position: relative; background-color: rgb(255, 255, 255);">c≥a;a≥bc≥a;a≥b thì VT(1)<=VP(1). Dấu = xảy ra <=>a=b=c <=>x=y=z.đúng ko nhỉ ////mk chỉ giải v thui nêuus ko đứng cx đừng trách nhé
Giải: Đặt a=x+2011;b=y+2011;c=z+2011 (a;b;c>=0)thay vào hệ. suy ra a+b+1+c+2=c+a+1+b+2&lt;=&gt;c+2−c=(a+1−a)+(b+2−b+1)&lt;=&gt;c+2−c+1+c+1−c=VP&lt;=&gt;1c+1+c+2+1c+1+c=1a+a+1+1b+1+b+2" role="presentation" style="display: inline; font-size: 14px; word-spacing: 0px; color: rgb(40, 40, 40); font-family: helvetica, arial, sans-serif; position: relative; background-color: rgb(255, 255, 255);">a√+b+1−−−−√+c+2−−−−√=c√+a+1−−−−√+b+2−−−−√<=>c+2−−−−√−c√=(a+1−−−−√−a√)+(b+2−−−−√−b+1−−−−√)<=>c+2−−−−√−c+1−−−−√+c+1−−−−√−c√=VP<=>1c+1−−−−√+c+2−−−−√+1c+1−−−−√+c√=1a√+a+1−−−−√+1b+1−−−−√+b+2−−−−√a+b+1+c+2=c+a+1+b+2<=>c+2−c=(a+1−a)+(b+2−b+1)<=>c+2−c+1+c+1−c=VP<=>1c+1+c+2+1c+1+c=1a+a+1+1b+1+b+2 (1)Với c&#x2265;a;a&#x2265;b" role="presentation" style="display: inline; font-size: 14px; word-spacing: 0px; color: rgb(40, 40, 40); font-family: helvetica, arial, sans-serif; position: relative; background-color: rgb(255, 255, 255);">c≥a;a≥bc≥a;a≥b thì VT(1)<=VP(1). Dấu = xảy ra <=>a=b=c <=>x=y=z.mk ko bt là có đúng hay ko nữa ?????? vote cho mk nhé