July 28, 2015 Problem of the week #174 July 28th, 2015 Leave a comment Here is this week’s POTW: —– Three positive real numbers $x,\,y,\,z$ are such that $x^2+5y^2+4z^2-4xy-4yz=0$. Can $x,\,y,\,z$ form the sides… Advertisements Share this:TwitterFacebookGoogleLike this:Like Loading... Related Posted by ronaldconnelly423.