Without the values being able to find the values of x, y, and z, we have to use a process of deduction. 6+8+4=18, so if the highest answer is 15 one of the variables has to be a zero. x=1 and z ≤ 2. We know that y = 0, this will eliminate 8 out of the equation.So we are left with 6+4=10 or 6(1)+4(2)= 14.
Now we can eliminate our answers, last answer is wrong, the first three have possibilities. However, the first and the second are pretty much the same answer, there can only be one answer. x+y+z≤12