Cho ba số thực dương a, b, c. CMR: b+c/ a + c+a/ b+ a+b/c >=6
Giải thích
Ta có:
b+ca+c+ab+a+bc=1+b+ca+1+c+ab+1+a+bc−3=a+b+ca+b+c+ab+c+a+bc−3=a+b+c1a+1b+1c−3≥9−3=6
Ta có:
b+ca+c+ab+a+bc=1+b+ca+1+c+ab+1+a+bc−3=a+b+ca+b+c+ab+c+a+bc−3=a+b+c1a+1b+1c−3≥9−3=6