National cell charges a $5 flat fee for a text messaging plan and $0.15 per text. world wireless doesn’t charge a flat fee , but it charges $0.19 per text. which inequality and solution represent the number t of texts for which world wireless is cheaper then national cell ?

For this case, the first thing we must do is define a variable.
 We have then:
 t: number of texts
 We now write the expression for each plan:
 National cell:
 
 World wireless:
 
 The inequality for which World wireless is cheaper than national cell is:
 
 Solving for t we have:
 
 
 
 
 
 An inequality and solution that represent the number of texts for which world wireless is cheaper then national cell is: