Answer:
$8300
Explanation:
First, you need to know the formula for this type of question.
The formula is I = Prt. These variables are: I = Interest, P = Principle investment, r = Rate, and t = Time.
Your equation will be 581 = P(0.07)(1), since 0.07*1 is 0.07, you'll earn only 7% interest.
So, we broke down the equation to 581 = P(0.07), and you have to isolate P.
Since you have to isolate P, you divide 0.07 from both sides of the equation, which is 581/0.07 = 8300.
So, your principle investment is $8300.
Good luck!