The annual interest on a 9000 investment exceeds the interest earned on a $7000 investment by $145. the $9000 is invested at a 0.5% higher rate of interest than the $7000. what is the interest rate of each investment?

The $9000 investment was at 5.5% interest and $7000 investment was at 5% interest rate.

Step-by-step explanation:

Let x% interest rate is applicable to the $9000 investment.

So, the interest earned in one year from this investment is

Again, assume that the interest rate of $7000 investment y%.

So, the interest earned in one year from this investment is

By the condition given, 90x - 70y = 145 ....... (1)

Now, the $7000 is invested at a 0.5% lesser rate of interest than the $9000.

Hence, x - y = 0.5 ......... (2)

⇒ 70x - 70y = 35 ............ (3)

Now, solving equations (1) and (3) we get,

90x - 70x = 145 - 35 = 110

⇒ 20x = 110

⇒ x = 5.5%

So, from equation (2) we get, y = x - 0.5 = 5.5 - 0.5 = 5%

Therefore, the $9000 investment was at 5.5% interest and $7000 investment was at 5% interest rate. (Answer)

the monthly balance will be $75,000

1 + (6 / x - 1)

step-by-step explanation:

divide using polynomial division.