1.1 Investigation: Ordered Pairs and Solutions
An equation in one variable, such as 2x + 1 = 7,
has one real value of x as a solution.
2x + 1 = 7
2x = 6
x = 3 The solution is 3.
How many solutions does the
equation 2x + y =9 have?
infinite
number
One
Ten
infinite
number
Find three ordered pairs that
satisfy the equation 2x + y = 9.
Which ordered pair satisfies
the equation x-y=-1?
(2,3)
(-1,-2)
(-5,6)
Now work with a partner to complete
parts 2 and 3 of the investigation on
pages 4 and 5 of your textbook.
Write complete answers in your notebook.
From the investigation...
1. Identify the ordered pair that
satisfies both equations.
y=2x-1
y=-x+5
(2,3), (1,1), (-1,6)
From the investigation...
2. C = 10n + 25
C = 15n + 10
(3,__?)
What number of days gives equal costs
for running the ad in each newspaper?
Find the point of intersection on the
graph.
From the investigation...
3. y = 2x + 1
y = 2x + 3
Explain why no ordered pair satisfies
both equations.