Answer:
Colombian coffee: 100 kg
Ethiopian coffee: 200
Explanation:
Let x represent kg of Colombian coffee and y represent kg of Ethiopian coffee.
We have been given that the mixture of coffee is 300 kg. We can represent this information in an equation as:
![x+y=300...(1)](https://img.qammunity.org/2021/formulas/mathematics/high-school/rfth9p76y04yifktsys61cerxptdp5rwdx.png)
![x=300-y...(1)](https://img.qammunity.org/2021/formulas/mathematics/high-school/7r0p00ce1x6bwvclk4uh6pmv32g5fuqya6.png)
We have been given that Starstruck coffee shop mixed Colombian coffee worth $5 per kilogram with Ethiopian coffee worth $8 per kilogram.
Cost of x kg of Colombian coffee would be
and Cost of y kg of Ethiopian coffee would be
.
The mixture is to sell for $7 per kilogram. We can represent this information in an equation as:
![5x+8y=7(300)...(2)](https://img.qammunity.org/2021/formulas/mathematics/high-school/6yco2gncw6amfqnqrtz22o83tetngx96d8.png)
Upon substituting equation (1) in equation (2), we will get:
![5(300-y)+8y=7(300)](https://img.qammunity.org/2021/formulas/mathematics/high-school/ffqbx56q9lfzt6nspmfeasu3dfgk8tfgzb.png)
![1500-5y+8y=2100](https://img.qammunity.org/2021/formulas/mathematics/high-school/q78orj1c4xyf20dh2uu0qem1nr4qedfubm.png)
![1500+3y=2100](https://img.qammunity.org/2021/formulas/mathematics/high-school/39sy6408xg922dpkhyekjo7slqagznenpx.png)
![3y=2100-1500](https://img.qammunity.org/2021/formulas/mathematics/high-school/mkjoyesihrmazle7b4eah4g24ypglvsq89.png)
![3y=600](https://img.qammunity.org/2021/formulas/mathematics/high-school/fjf7j0zsw94kd4aqug72j0rtk60cnkv4cs.png)
![(3y)/(3)=(600)/(3)](https://img.qammunity.org/2021/formulas/mathematics/high-school/67bqw0egziqtpgvb23qe5w9sgp69ej79t3.png)
![y=200](https://img.qammunity.org/2021/formulas/mathematics/middle-school/vqxnaucly4law19o58yd35gfx4ta1h0424.png)
Therefore, 200 kg of Ethiopian coffee should be used.
Upon substituting
in equation (1), we will get:
![x=300-200=100](https://img.qammunity.org/2021/formulas/mathematics/high-school/g2e284kismtrn9mb1q7p195iuqt3cy467b.png)
Therefore, 100 kg of Colombian coffee should be used.