Answer: The system of equations is,
![0.15x+0.03y=300](https://tex.z-dn.net/?f=0.15x%2B0.03y%3D300)
![x+y=12000](https://tex.z-dn.net/?f=x%2By%3D12000)
Step-by-step explanation:
For first account,
Investment = x,
Annual rate of interest = 1.5 %
Time = 1 year
Thus, the total interest by one account,
![I_1=\frac{x\times 1.5\times 1}{100}=0.015x](https://tex.z-dn.net/?f=I_1%3D%5Cfrac%7Bx%5Ctimes%201.5%5Ctimes%201%7D%7B100%7D%3D0.015x)
Now, for second account,
Investment = y
Annual rate of interest = 1.5%
Time = 1,
Hence, the interest by the second account,
![I_2=\frac{y\times 3\times 1}{100}=0.03y](https://tex.z-dn.net/?f=I_2%3D%5Cfrac%7By%5Ctimes%203%5Ctimes%201%7D%7B100%7D%3D0.03y)
Thus, the total interest,
![I=I_1+I_2=0.015 x + 0.03y](https://tex.z-dn.net/?f=I%3DI_1%2BI_2%3D0.015%20x%20%2B%200.03y)
According to the question,
![I=300](https://tex.z-dn.net/?f=I%3D300)
![\implies 0.15x+0.03y = 300](https://tex.z-dn.net/?f=%5Cimplies%200.15x%2B0.03y%20%3D%20300)
Now, total investment = 12000,
⇒ x + y = 12000
Hence, the required system of equations, to solve for how much money Leroy invested in the two accounts is,
,
![x+y=12000](https://tex.z-dn.net/?f=x%2By%3D12000)