The answer for the first question is a. In this problem, we are trying to figure out any numbers that belong to both set X and Y. Set X, has numbers that are less than 10. {etc... -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9} This can go on forever, because there is no specified limitation, besides the numbers having to be lower than 10. Set Y, has numbers that are even. {etc... -4, -2, 0, 2, 4, 6, 8, 10, 12, etc...} This also can go on forever, because there is no specified limitation, besides the numbers having to be even. The only numbers that belong in both set X and Y are {0, 2, 4, 6, 8}. Therefore, answer to the problem is a: {0, 2, 4, 6, 8}.
The answer for the second question is a. You need to replace z with 0, 1, 2, or 3 and solve the equation on the right side of the inequality sign. The answer to the equation must be less than 6. If you replace z with 0: 0 (10-0) = 0. 0 is less than 6. If you replace z with 1: 1 (10-1) = 9. 9 is greater than 6. If you replace z with 2: 2 (10-2) = 16. 16 is greater than 6. If you replace z with 3: 3 (10-3) = 21. 21 is greater than 6. Therefore, 0 is the answer.
You should find that your system doesn't have solutions. This is also confirmed by the fact that the determinant of the matrix of the coefficient of the variables x, y and z is equal to zero.
