Qlt1

QLT1

1. Provide an algebraic representation of the account balance (y) for each of the two savings plans.

Note: Use the variable x to represent the number of months.

Solution: For plan A,

y=400+20x …………………….. (1)

For plan B,

y=600+10x ……………………. (2)

2. Solve the system of equations algebraically to determine when the two savings plans yield identical balances and state this balance.

Solution: By (1)(2), we have

400+20x=600+10x

i.e., 10x=200

So, x=200/10=20

So, after 20 months the two savings plans yield identical balances. This balance is

y=400+20*20=800 dollars.

3. Graph the system of equations on a single coordinate plane to illustrate the graphical solution.

• Label each axis of the coordinate plane with descriptive labels.

• Label each relevant intercept as "x-intercept" or "y-intercept" and include the ordered pair.

• Label the graphical solution of the system of equations as "solution" and include the ordered pair.

• In a legend, indicate which saving plan and which equation corresponds with each line.

[pic]

a. Use the graph to determine the following:

1. Determine which plan yields the greatest balance if the person stops saving after 14 months.

From the below graphs, we can see that the Plan B yields the greatest balance if the person stops saving after 14 months.

[pic]

2. Determine which plan yields the greatest balance if the person stops saving after 23 months.

From the below graphs, we can see that the Plan A yields the greatest balance if the person stops saving after 23 months.

[pic]

4. Explain which quadrant(s) of the graph is/are relevant to this problem.

As the x represents the number of months, and y represents the account balance, they must be...