Math/Word - Finance Problem?

Question

Two investments earn an annual income of $478.40. One investment earns an annual simple interest rate of 6.5%, and other investment earns an annual simple interest rate of 5.4%. The total amount invested is $7,800. How much is invested in each account.

Thanks

Answer 1

I have to run, so I'll just set this up for you:

Let x and y represent the two different investments.

.065x + .054y = 478.40

x + y = 7800

y = 7800 - x

,065x + .054 (7800 - x) = 478.40

The rest is just arithmatic.