For her cell phone plan Heather pays $30 per month plus $0.05 per text. She wants to keep her bill under $60 per month. What inequality represents how many texts Heather can send each month while staying within her budget?
The monthly cost is
Heather wants to keep this less than
Note that we can also subtract
We can also divide both sides by
This is the most useful inequality, since it tells Heather she needs to send fewer than 600 texts per month, or about 20 per day.