Nena invested some money at 7% interest and the same amount at 10%. Her total interest for the year was $850. How much did she invest at each rate?

x = amount invested

.07x + .10x = 850

Solve for x, amount invested

i got it.thank u!

michael borrowed $ 700 from his father. He promise to pay back the $700 with interesd in 9 moths. If michael pays his father 6% simple interest how much does he owe at the end of 9 moths?

phyllis invested $10,000, a portion earning a simple interest rate of 4.5 % per year and the rest earning a rate of 4% per year. after one year the total interest earned on these investments was $413.00. how much money did she invest at each rate?

To determine how much Nena invested at each rate, we can set up a system of equations using the given information.

Let's assume that Nena invested x dollars at 7% interest. This means she also invested x dollars at 10% interest, as the amounts are the same.

The interest earned on the amount invested at 7% can be calculated by multiplying the amount invested by the interest rate expressed as a decimal, which is 0.07x.

Similarly, the interest earned on the amount invested at 10% is 0.10x.

According to the given information, the total interest earned in a year was $850. So, we can set up the following equation:

0.07x + 0.10x = 850

Combining like terms, we have:

0.17x = 850

Solving for x, we divide both sides of the equation by 0.17:

x = 850 / 0.17

Evaluating the right side of the equation, we find:

x = 5000

Hence, Nena invested $5000 at each rate -- $5000 at 7% interest and $5000 at 10% interest.