Answer:
2000 was the amount of the investment in the savings account
6000 was the amount of the investment in the payment of bonds
8000 was the amount of the investment in the money market
Step-by-step explanation:
In this case, a system of equations must be generated with the information given in the statement.
Let x be the amount of the investment in the savings account
Let y be the amount of the investment in the payment of bonds
Let z be the amount of investment in the money market
Now, the first equation would be that of total investment:
x + y + z = 16000
The second equation is that of interest:
0.07 * x + 0.09 * y + 0.12 * z = 1640
Last, her equation has invested three times more in the bond payment than in the savings account:
3 * x = y
So we have 3 equation with 3 unknowns. Therefore there is a solution.
x + y + z = 16000
0.07 * x + 0.09 * y + 0.12 * z = 1640
3 * x = y
In order not to make the answer too extensive, we will solve the system of equations with the help of symbolab, here is the step-by-step of everything they do in a very detailed and precise way.
https://es.symbolab.com/solver/step-by-step/x%20%2B%20y%20%2B%20z%20%3D%2016000%3B%200.07%20%5Ccdot%20x%20%2B%200.09%20%5Ccdot%20y%20%2B%200.12%20%5Ccdot%20z%20%3D%201640%3B%203%20%5Ccdot%20x%20%3D%20y
From this, the results are as follows:
x = 2000
y = 6000
z = 8000
Thus
2000 was the amount of the investment in the savings account
6000 was the amount of the investment in the payment of bonds
8000 was the amount of the investment in the money market
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