Can someone help me

Question

A combined total of $32,000 is invested in two bonds that pay 5% and 7% simple interest. The annual interest is $2,000.00. How much is invested in each bond?

Answer 1

Let x = $ invested at 5%

Let y = $ invested at 7%

As far as total investment goes it must be true that:

x + y = 32000

As far as total interest earned:

.05x + .07y = 2000 (if you do not like working with decimals--like me--multiply every term by 100)

5x + 7y = 200000

x + y = 32000 (first equation repeated)

At this point you have two equations with two unknowns ( a system of linear equations). Use the substitution method (solving for y, gives y = 32000 - x ) and substitute for y in the other equation. Or, use addition elimination, perhaps multiplying by -5 to get -5x - 5y = -160000 and add to 5x+7y = 200000.

You should be able to take it from there.