Respuesta :
Answer: he invested $2000 in stocks and $7000 in bonds
Step-by-step explanation:
Let x represent the amount of money invested in stocks.
Let y represent the amount of money invested in bonds.
Total amount of money invested in stocks and bonds is
x + y = 9000
x = 9000 - y - - - - - - - - - 1
The formula for simple interest is expressed as
I = PRT/100
Where
P is the principal or initial amount.
T is the duration in years
R is the number rate.
For the stocks,
R = 6%
T = 1 year
P = x
I = (x × 6 × 1)/100 = 0.06x
For the bonds,
R = 7%
T = 1 year
P = y
I = (y × 7 × 1)/100 = 0.07y
At the end of the year, the total interest from these investments was $610. This means that
0.06x + 0.07y = 610 - - - - - - - -2
Substituting equation 1 into equation 2, it becomes,
0.06( 9000 - y) + 0.07y = 610
540 - 0.06y + 0.07y = 610
- 0.06y + 0.07y = 610 - 540
0.01 y =70
y = 70/0.01 = 7000
x = 9000 - 7000
x = $2000
