You have that Acme H2O charges 15 fee and7.50 per 5-gallon. Furthermore, Best water charges 24 fee and 6.00 per 5-gallon.
In order to find the amount of five-gallons that the office have to buy, you can write, in an akgebraic form, the previous realtions, just as follow:
24 + 6x < 15 + 7.5x
That is, cost of Best water less than cost of Acme H20. x is the amount of five-gallons
You solve the previous inequality, as follow:
24 + 6x < 15 + 7.5x subtract 6x both sides and subtract 15 both sides
24 - 15 + 6x - 6x < 15 - 15 + 7.5x - 6x simplify
9 < 1.5x divide between 1.5 both sides
9/1.5 < 1.5x/1.5 simplify
6 < x
6 < x is the same as x > 6. Hence, Office would have to buy lower than 6 five-gallons.
