Two investments totaling $23,500 produce an annual income of $795. One investment yields 2% per year, while the other yields 7% per year. How much is invested at each rate?

Let x = amount at 2%

Then 23,500 - x = amount at 7%.
Total interest = $795
0.02x + 0.07(23,500-x) = 795
Solve for x and 23,500 - x.
Post your work if you get stuck.