Problem
Juanita wants to buy a computer. She needs to earn at least 400 dollars. If she makes 9 dollars an hour and has already saved 40 dollars, how many hours does she need to work?
Solution
Let x the number of hours required we can set up the following inequality:
40 + 9x > 400
And now we can solve for x we can subtract 40 and we got:
9x > 360
And then we got:
x> 40
So then Juanita needs to work at least 40 hours
And the graph of the inequality is given by: