Question

Lisa invests 4000 in two types of bonds, bond A and B. Bond A offers a 10% return, and bind B offers 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 _____.

Answer 1

Given data:

The expression for the total amount iis x+y=4000.

The total investment is 340.

The expression for the total investment is,

`0.1x+0.06y=340`

Substitute (4000-x) for y in the above expression.

`\begin{gathered} 0.1x+0.06(4000-x)=340 \\ 0.1x+240-0.06x=340 \\ 0.04x=100 \\ x=2500 \end{gathered}`

The value of y is,

`\begin{gathered} y=4000-2500 \\ =1500 \end{gathered}`

Thus, the system of equations that define the situation are x+y=4000, and 0.1x+0.06y=340. The amount Lisa invested in 10% rate is $2500, and the amount Lisa invested in 6% rate is $1500.