Let:
x = Cost of each kilogram of honey drew
y = Cost of each kilogram of watermelon
Once, she used 3 kilograms of honeydew melon and 3 kilograms of watermelon, which cost her $12. So:
![3x+3y=12_{\text{ }}(1)](https://img.qammunity.org/2023/formulas/mathematics/college/gg3lqysys8fibpovpp4ecy9o35b3i3jqy8.png)
She also used 2 kilograms of honeydew melon and 1 kilogram of watermelon, spending a total of $6 on the melons. So:
![2x+y=6_{\text{ }}(2)](https://img.qammunity.org/2023/formulas/mathematics/college/g01ofs6toih9rgdrbncncdp1qevgah87ui.png)
From (2) solve for y:
![y=6-2x_{\text{ }}(3)](https://img.qammunity.org/2023/formulas/mathematics/college/i82ufb2wc4wbyztj96699tx2kdnn6410kj.png)
Replace (3) into (1):
![\begin{gathered} 3x+3(6-2x)=12 \\ 3x+18-6x=12 \\ -3x=-6 \\ x=-(6)/(-3) \\ x=2 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/6h2xwp327kcijd105fqw6203cs2zfrdsq5.png)
Replace x into (3):
![\begin{gathered} y=6-2(2) \\ y=2 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/7ovjcdirmqyqov415gs78e2xb67a77z3yg.png)
Answer:
Honeydew melon costs 2 dollars per kilogram
Watermelon costs 2 dollars per kilogram