Answer :
Answer:
- $4000 at 9% and $6000 at 7%
Step-by-step explanation:
Let the amount invested at 9% be x.
Then the amount invested at 7% is 10000 - x.
The amount of interest after one year is $780.
Set up equation to represent this:
- 0.09x + 0.07(10000 - x) = 780
- 0.09x + 700 - 0.07x = 780
- 0.02x = 780 - 700
- 0.02x = 80
- x = 80/0.02
- x = 4000
Amount invested at 7% is:
- 10000 - 4000 =
- 6000
Answer:
Milan invested:
- $4,000 into the account earning 9% interest.
- $6,000 into the account earning 7% interest.
Step-by-step explanation:
Given information:
- Total amount invested = $10,000.
- Account A = 9% simple interest per year.
- Account B = 7% simple interest per year.
- Total interest earned after one year = $780.
Let x be the amount invested in Account A.
Therefore, the amount invested in Account B is (10000 - x).
Simple Interest Formula
I = Prt
where:
- I = Interest earned.
- P = Principal invested.
- r = Interest rate (in decimal form).
- t = Time (in years).
Create two equations using the given information:
[tex]\begin{aligned}\textsf{Interest: Account A} &= x \cdot 0.09 \cdot 1\\& = 0.09x\end{aligned}[/tex]
[tex]\begin{aligned}\textsf{Interest: Account B} &= (10000 - x) \cdot 0.07 \cdot 1 \\& = 0.07(10000 - x)\\& = 700-0.07x\end{aligned}[/tex]
As the total interest earned was $780, set the sum of the two found equations to 780 and solve for x:
[tex]\begin{aligned}\implies 0.09x+700-0.07x&=780\\0.02x+700&=780\\0.02x&=80\\x&=4000\end{aligned}[/tex]
Therefore, Milan invested:
- $4,000 into the account earning 9% interest.
- $6,000 into the account earning 7% interest.