Cho a,b > 0, CMR : a/ b+1 + b/a + 1 + 1/a + b lớn hơn bằng 3/2

Từ x+y+z1x+1y+1z≥9

⇒ab+1+1+ba+1+1+1a+b+1−3=a+b+11a+b+1a+1+1b+1−3≥92−3=32