Eric C. answered • 10/05/16

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Hi Karlie.

Let's say the amount you invest in the 6% account is defined as X. Since your problem states you invested $2000 more in the account that earns 9% interest, that means you invested X+2000 in your 9% account.

The simple interest formula is:

A = Prt

Where A is the amount returned, P is the principal invested, r is the rate of return, and t is the time.

I'm going to write two different formulas.

A

_{6%}= P_{6%}*r_{6%}*tA

_{9%}= P_{9%}*r_{9%}*tYou earned a total of $405 in one year from your interest, so that means when t = 1,

A

_{6%}+ A_{9%}= 405We said P

_{6%}was X, and P_{9%}was X+2000r

_{6%}= 0.06, and r_{9%}= 0.09So

A

_{6%}= X*0.06*1A

_{9%}= (X+2000)*0.09*1Therefore

0.06*X + 0.09*(X+2000) = 405

0.15X + 180 = 405

0.15X = 225

X = 1500

So the amount you invested in the 6% account is $1500, meaning the amount you invested in your 9% account is $1500 + $2000 = $3500.

Hope this helps.