The student's council is setting up a concession stand for a 24 hour relay. They plan on selling hot dogs and humburgers. A maximum of 600 hamburgers and hot dogs are needed. From the previous year's relay the demand should be at least four times as many hot dogs as hamburgers. Write a system of linear inequalities to represent this situation.

So far I have x+y is less than or equal to 600.

Is this correct? And if it is how would I right that there needs to be at least four times as many hot dogs as hamburgers in the other inequality?

Question

The student's council is setting up a concession stand for a 24 hour relay. They plan on selling hot dogs and humburgers. A maximum of 600 hamburgers and hot dogs are needed. From the previous year's relay the demand should be at least four times as many hot dogs as hamburgers. Write a system of linear inequalities to represent this situation.

So far I have x+y is less than or equal to 600. 

Is this correct? And if it is how would I right that there needs to be at least four times as many hot dogs as hamburgers in the other inequality?