Brianna cruz earned $130 in simple intrest in 9 months at an annual interest rate of 8%. How much money did she invest?

She invested $2,167

Explanation:

As interest rate is not compounded, the 9-month interest of a 8% annual interest is simply:

8% * 9 / 12 = 6%

Let A be the amount of money she invest. After 9 month she will receive:

A * 0.06 dollars.

And the actual amount is $130. So she invested

A = $130 / 0.06 = $2,167