anonymous 4 years ago 2r + 1 < 5 and –2r – 4 ≥ 6 Is it empty ?

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

2. anonymous

This when there is 'or' but now we are dealing with 'and' => intersection. When you want to graph it will look like : |dw:1328566495750:dw|

3. anonymous

Or is it all real numbers ?

no the real picture is like this

|dw:1328566721597:dw|

|dw:1328566814637:dw|

7. anonymous

oohh! So the intersection is only on point r<=-5 ?

no, it's the intersection of the two intervals so the intersection area are all numbers from -infinity to -5, including -5

9. anonymous

Okay, what is the solution set ?

if the question is: ''Is it empty?'' your answer is ''no'' and if they ask you to write the solution your answer is: x$\epsilon(-\infty,-5]$

11. anonymous

Okay, thank you!!