Try a value that satisfies the inequality, and one that doesn't--preferably at the boundary. Example 3x + 2 > 4 has solution 3x > 2 x > 2/3 We can pick a value x=1 and see if the inequality is satisfied. 3(1) + 2 > 4 (check for x=1. We know 1 > 2/3.) 3+2 > 4 5 > 4 (yes, the inequality is satisfied) We can also pick the boundary value x=2/3 to see if the inequality is not satisfied. 3(2/3) + 2 > 4 (check for x=2/3. We know that 2/3 > 2/3 is false.) 2 + 2 > 4 4 > 4 (no, the inequality is not satisfied. We see that the left side is equal to the right side, as we expect to have happen at the boundary.)