Since time is one year in I = prt then the options below can be used

If you've had Algebra you can use Systems of Equations to solve this problem

x + y = 30,000 for the parts of the Principal

.09x + .08y = 2420 For the rates and total Earnings

Or you can use a substitution knowing your Principal, Rates and Total Earnings

Remember to write the rates as decimals.

First you can put everything in terms of x as follows

x + y = 30,000

y = 30,000 - x

y can be rewritten as 30,000 - x

Using the rates to total earnings we have

.09x + .08(30,000 - x) = 2420

Then just solve for x.

Try the above let me know if you have any questions.