Answer:
900 large boxes were sold, and 750 small boxes.
Explanation:
This question can be solved by a system of equations.
I am going to say that:
x is the number of large boxes of cookies sold.
y is the number of small boxes of cookies sold.
A total of 1,650 boxes of Girl Scout cookies were sold last week.
This means that
![x + y = 1650](https://img.qammunity.org/2022/formulas/mathematics/college/2iheorj6merwwx43alfqh497f7qe7ag5a7.png)
So
![x = 1650 - y](https://img.qammunity.org/2022/formulas/mathematics/college/o2v9uno3luoksseg8eysfwoix0wlu4a4sj.png)
Each large box cost $3.50 and each small box cost $2.00. The Girl Scout group earned $4,650.
This means that
![3.5x + 2y = 4650](https://img.qammunity.org/2022/formulas/mathematics/college/b38nf7xem5l5myfvipo77jeighbuq8daw3.png)
Since
![x = 1650 - y](https://img.qammunity.org/2022/formulas/mathematics/college/o2v9uno3luoksseg8eysfwoix0wlu4a4sj.png)
![3.5(1650 - y) + 2y = 4650](https://img.qammunity.org/2022/formulas/mathematics/college/bisvnupidxh9z63i99i34b690q8z9rs21c.png)
![5775 - 3.5y + 2y = 4650](https://img.qammunity.org/2022/formulas/mathematics/college/859koe7cuhhftbhx2hkyub5zgkxuz5lv2r.png)
![1.5y = 1125](https://img.qammunity.org/2022/formulas/mathematics/college/6dzrkcpabhu09ckkmnaz456omy1ds6cli4.png)
![y = (1125)/(1.5)](https://img.qammunity.org/2022/formulas/mathematics/college/ykbd9stk82t9nhatmga2njdnjhv4mqq07s.png)
![y = 750](https://img.qammunity.org/2022/formulas/mathematics/college/c0gt72ot28brvl0zu1a72lyoqjymk4bhna.png)
![x = 1650 - y = 1650 - 750 = 900](https://img.qammunity.org/2022/formulas/mathematics/college/hzggpcct265pru2qdbanbmw7qt4dan91cq.png)
900 large boxes were sold, and 750 small boxes.