Helene invested a total of $1,000 in two simple-interest bank accounts. One account paid 6% annual
interest; the other paid 7% annual interest. The total amount of interest she earned after one year was
$66. Enter and solve a system of equations to find the amount invested in each account. Enter the interest
rates in order as given in the problem. (Hint: Change the interest rates into decimals first.)
x+y = 1,000
0.06
x+ 0.07
y = 66
Helene invested $
at 6% and $
at 7%.

Question

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Respuesta :

calculista calculista · Answer 1 · 2019-11-30T12:01:58+01:00

Answer:

Helene invested $ 400 at 6% and $ 600 at 7%.

Step-by-step explanation:

Let

x -----> the amount invested at 6%

y -----> the amount invested at 7%

we know that

The interest earned with the amount invested at 6% plus the interest earned by the amount invested at 7% must be equal to $66

Remember that

[tex]6\%=6/100=0.06\\7\%=7/100=0.07[/tex]

so

[tex]x+y=1,000[/tex] ----> equation A

[tex]0.06x+0.07y=66[/tex] ----> equation B

Solve the system of equations by graphing

The solution of the system is the intersection point both graphs

using a graphing tool

The solution is the point (400,600)

see the attached figure

therefore

Helene invested $ 400 at 6% and $ 600 at 7%.