Question 51695
{{{x/2-x + y/2-y + z/2-z >=3/5}}}


{{{-x/2-y/2-z/2 >= 3/5}}}


after multiplying both sides with -2. we will need to change sides because it is negative.

{{{-6/5 >= x+y+z}}}


{{{-6/5 >= 1}}}


a positive number is always bigger than a negative so 1 is bigger than {{{-6/5}}}. So it is proven that equation is in fact WRONG. But if you had written > instead of < of course the equation will be correct or if you had forgotten to put (-) before {{{5/3}}} it would have been correct.