Final answer:
The maximum value of z = 3x1 + 5x2 + 6x3 does not exist without constraints on the values of x1, x2, and x3.
Step-by-step explanation:
To determine the maximum value of z = 3x1 + 5x2 + 6x3, we need to maximize the values of x1, x2, and x3. Since we are not given any constraints or specific values for x1, x2, and x3, we can assume that these variables can take on any real value. In that case, there is no maximum value for z since the values of x1, x2, and x3 can be infinitely large.