Given that x, y and b are real numbers and x < y, b < 0, then

18

Show that the solution set of the following system of linear inequalities is an unbounded region 2x + y ≥ 8, x + 2y ≥ 10, x ≥ 0, y ≥ 0

19

If x < 5, then

21

If – 3x + 17 < – 13, then

22

If x is a real number and |x| < 3, then