Let P be the set of points [x1,x2,x3] with x1 + x2 + x3 = 1. Draw P.
My thoughts on this is that x1, x2, and x3 aren't defined with definite values, so they can be anything really. But their sum has to equal to 1. Would it be reasonable to say that x1 = x2 = x3 = 1/3? Or just use different values that satisfy the equation?
Then when it comes to actually drawing P, would it, when all entries are the same value, just be a square(values 1/3), and every other drawing of P with different values for the entries still be some sort of 4-sided shape?