1. Section 9.1 – Systems of Equations
Application Problems
P. 650 #64-78 evens

2. Revenue meets cost when 233333 units are sold.
64.
Revenue meets cost when units are sold.
The revenue and cost is approximately $

3. Revenue meets cost when 3133 units are sold.
66.
Revenue meets cost when 3133 units are sold.
The revenue and cost is approximately $

4. 68.
Selling 400 units would be the break-even point.

5. 70.
b) As the amount at 6.5% increases,
the amount at 8.5% decreases. The
amount of interest also decreases.
c) To attain $1600 per year,
invest $5000 at 6.5% and
invest $15000 at 8.5%.

6. 72.
Would have to sell more than books for second
salary offer to be better.

7. 74.
The market equilibrium is
bushels per day.

8. 76. y x
2x + 2y = 280
y = x – 20
80 x 60

9. 78. y x
2x + 2y = 210
x = 1.5y
63 x 42