Question

Michael has $12,500 to invest. he invests part in an account which earns 4.2% annual interest and the rest in an account which earns 6.2% annual interest. he earns $669.50 in interest at the end of the year. how much was invested at each rate?

Answer 1

Suppose he invest x dollars in one account, y in the other
x+y=12,500
0.042x+0.062y=669.50
multiple the first equation by 0.042: 0.042x+0.042y=525
subtract this new equation from equation 2: 0.02y=144.50
y=7225
x=12500-7225=5275

Answer 2

The answer is $5,275 at 4.2%, $7,225 at 6.2%

Which in Edgenuity is D)