1. Finding the y-intercept
Use the green definition books to get the definition or meaning of the Y-intercept and write it in your ISN notebook.

2. Linear Function-
The equation Ax + By = C represents a linear function as long as B = 0.

3. Graph a Function
Graph the function y = – 3x + 1 with domain x ≤ 0. Then identify the range of the function.
SOLUTION x
– 1
– 2
– 3
– 4 y 1 4 7 10 13
STEP 1
Make a table.
STEP 2
Plot the points.
STEP 3
Connect the points with a ray
because the domain is restricted.
STEP 4
Identify the range. From the graph, you can see that all points have a y-coordinate of 1 or more, so the range of the function is y ≥ 1.

4. “Graph Using Intercepts”
x-intercept-
the x-coordinate of the point where the graph crosses the x-axis
To find the x-intercept, solve for ‘x’ when ‘y = 0.’
Find the x-intercept of the graph 2x + 7y = 28.
2x + 7y = 28
2x + 7(0)= 28
2x = 28
x = 14

5. Section 4.3 “Graph Using Intercepts”
y-intercept-
the y-coordinate of the point where the graph crosses the y-axis
To find the y-intercept, solve for ‘y’ when ‘x = 0.’
Find the y-intercept of the graph 2x + 7y = 28.
2x + 7y = 28
2(0)+ 7y= 28
7y = 28
y = 4

6. Use Intercepts to Graph an Equation
Graph the equation x + 2y = 4.
Find the x-intercept
Find the y-intercept
x + 2y = 4
x + 2y = 4
x + 2(0) = 4
0 + 2y = 4
x = 
x-intercept 4
y = 
y-intercept 2
Plot points. The x-intercept is 4, so plot the point (4, 0). The y- intercept is 2, so plot the point (0, 2). Draw a line through the points.

7. Use Intercepts to Graph an Equation
Graph the equation 6x + 7y = 42.
Find the x-intercept
Find the y-intercept
6x + 7y = 42
6x + 7y = 42
6x + 7(0)= 42
6(0) + 7y = 42
x = 
x-intercept 7
y = 
y-intercept 6
Plot points. The x-intercept is 7, so plot the point (7, 0). The y- intercept is 6, so plot the point (0, 6). Draw a line through the points.

8. Use a Graph to Find Intercepts
The graph crosses the x-axis at (2, 0). The x-intercept is 2.
The graph crosses the y-axis at (0, – 1). The y-intercept is – 1.

9. Use a Graph to Find Intercepts
The graph crosses the x-axis at (–4, 0). The x-intercept is –4.
The graph crosses the y-axis at (0, 2). The y-intercept is 2.

10. Problem Solving Using Linear Equations
You are working at a local park and are in charge of renting skateboards and bikes. You rent bikes for $8.00 a day and skateboards for $4.00 a day. At the end of the day you have made a profit of $1200.
Using the graph, make a table of values to show the different combinations of rentals that could have resulted in a $1200 profit.
Write an algebraic equation to represent the situation. Use ‘x’ for skateboards and ‘y’ for bikes.
4x + 8y = 1200
bikes 50 50
100
150
200
250
300
skateboards

11. 24
Homework
Text p. 229, #8-22 even #28-40 even, 46