Model the Problem Using a System of Linear Equations

Multiple Choice

Model the problem using a system of linear equations. Then solve using the augmented matrix. Suppose $24,000 is invested in three different accounts paying 3%, 4%, and 7%
Annual interest. The interest earned after 1 year is $1270, and the amount
Invested at 7% is equal to the sum of the amounts invested at 3% and 4%.
Find the amount invested at 3%.

A) $5000
B) $6000
C) $7000
D) $8000