Question

2r + 1 < 5 and –2r – 4 ≥ 6

Is it empty ?

Answer 1

no, from the first inequality you get r<2 and from the second you get r<=-5 so the answer is r<=-5

Answer 2

This when there is 'or' but now we are dealing with 'and' => intersection.

When you want to graph it will look like :