How do you solve and write the following in interval notation: # | 5x + 3 | >18#?

1 Answer
Jun 24, 2016

When you have the absolute value, you can remove it considering the two sign #\pm#. You have to be careful with the inequality because the #+# keep the direction of the inequality while the #-# inverte it.
In your case you have

#|5x+3|>18#

#5x+3>18# and #5x+3<-18#

#5x>15# and #5x<-21#

#x>3# and #x<-21/5#.

As interval you can say that #x in (-oo, -21/5) and (3, +oo)#.