You invested $20,000 in two accounts paying 2% and 9% annual interest, respectively. If the total interest earned for the year was $1520, how much was invested at each rate?
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The amount invested at 2% is?

invested 2%: $4,000. 9%: $16,000

Step-by-step explanation:

A: the amount invested 2%

B: the amount invested 9%

we have:

A + B = 20,000 => A= 20,000 - B

and 2%A+ 9%B = 1,520

=> 2%(20,000 - B) + 9%B = 1,520

=> 400 - 2% B + 9%B = 1,520

=> 7% B = 1120 => B = 16,000 => A= 4,000