TECHNOLOGY INSIGHTS EXERCISES 73 – 76
222 CHAPTER 4 Systems of Linear Equations
–10 10
10
–10
–10 10
10
–10
73.The table shown was generated by a
graphing calculator. The functions
defined by and are linear.
Based on the table, what are the
coordinates of the point of inter-
section of the graphs?
74.The functions defined by and
in the table are linear.
(a)Use the methods of Chapter 3
to find an equation for and
an equation for.
(b)Solve the system of equations
formed by Y 1 and .Y 2
Y 2
Y 1
Y 1 Y 2
Y 1 Y 2
75.The solution set of the system
is. Using slopes and y-intercepts, determine which one of the two
calculator graphs is the appropriate one for this system.
A. B.
51 1, - 226
y 2 =- 4 x+ 2
y 1 = 3 x- 5
76.Which one of the ordered pairs listed is the only
possible solution of the system whose graphs are
shown in the standard viewing window of a
graphing calculator?
A. B.
C. 1 - 15, 15 2 D. 1 - 15, - 152
1 15, - 152 1 15, 15 2
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10
–10
For each system, (a)solve by elimination or substitution and (b)use a graphing calculator to
support your result. In part (b), be sure to solve each equation for y first.
77.
2 x-y= 5
x+y= 10 78.
6 x+y= 5
Use each graph provided to work Exercises 79 – 82.
79.The figure shows graphs that represent supply
and demand for a certain brand of low-fat
frozen yogurt at various prices per half-gallon
(in dollars).
(a)At what price does supply equal demand?
(b)For how many half-gallons does supply
equal demand?
(c)What are the supply and demand at a price
of $2 per half-gallon?
Price per Half-Gallon
Number of Half-Gallons^0123456789 10 11
100
200
300
400
500
600
The Fortunes of Frozen Yogurt
Demand
Supply
