Vocabulary
These are the places where the graph crosses an axis.
X and Y intercepts
Solve 3x + 4y = 20 for y
y = -3/4x + 5
Graph the equation x + 2y = 4
Intercepts at x = 4 and y = 2
Find the slope of a line that passes through (-2, 0) and (1, 5)
5/3
The two things a graph needs to show a proportional relationship.
Needs to go through the origin and be a straight line.
This is the method used to graph when the equation is in standard form.
Sub zero
Solve -3x - y = 19 for y
y = -3x - 19
Graph the equation 2x - 5y = 1
x = 1/2 and y = -1/5
Find the slope of a line that passes through (-3, 4) and (2, -3)
-7/5
The two things that a table needs to show a proportional relationship.
Needs to have (0,0) and each ratio has the same constant.
This is what we call the rate of change of a graph.
Slope
Solve y = -2x + 4 for the constant
2x + y = 4
Graph the equation y = 2x + 4
Points at (0, 4) (1, 6) (-1, 2)
Find the slope of a line that passes through (-3, -1) and (2, -1)
0
This is the form of a proportional relationship.
y = kx
This is what happens when there is a constant rate of change and the graph begins at the origin.
It is proportional.
2y = 5x - 15
-5x + 2y = -15
Graph the equation x = -5
Vertical line
The kind of line has a slope of 0
Horizontal
Come up with a real-life situation word problem in which there is a proportional relationship.
Cost per ticket, etc.
This is the type of equation that makes a straight line (doesn't have to go through the origin, but could)
Linear equation
- 3x = 6y - 20
-3x - 6y = -20
Graph the line y = 3
Horizontal line
The kind of line that has an undefined slope.
Vertical
Come up with a real-life situation word problem in which there would not be a proportional relationship.
Rental fee, etc.