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).