Answer:
325 hamburgers were sold on Thursday.
Explanation:
Let h be the number of hamburgers and c be the number of cheeseburgers.
Using this information we can set up two equation as:
![h+c=593\\c=h-57](https://img.qammunity.org/2019/formulas/mathematics/middle-school/26syyt15g22ooe6j0jmds9zn4p5kawui3y.png)
Now we need to solve these two equations to get the value of number of hamburgers. For that we use substitution method as shown below:
![h+h-57=593\\2h-57=593\\2h=650\\h=325](https://img.qammunity.org/2019/formulas/mathematics/middle-school/61wvucunn445akv3bvvp5mlmv817fnthxk.png)
Therefore, the number of hamburgers sold on Thursday were 325.