Lisa invests $4,000 in two types of bonds, bond A and bond B. Bond A offers a 10% return, and bond B offers a 6% return. Lisa invests $x in bond A and $y in bond B. Her total return on the investment is $340. The system of linear equations defining the situation is . The amount Lisa invested at the rate of 10% is , and the amount she invested at the rate of 6% is .