the real numbers will have the values each = 1/3 for maximum value of the product ab+bc+ca thus 10101(ab+bc+ca)-12987abc equals 10101/3-12987/27=3367-481=2886

Give positive numbers a, b and c are such that ab + bc + ca + abc = 4, What is the value of 1/a+2 + 1/b+2 + 1/c+2 = ?

If abcde=1 (where a,b,c,d and e are all positive real numbers) then what is the minimum value of a+b+c+d+e?