NOTES for Section 2-2b:
Name______________________ Date_______
Linear Equations – graphing lines using x-intercept and y-intercept.
Vertical Line x = a
Horizontal Line y=b
Equation of Line
in Standard Form
Ax+By=C
A,B,C-integers
3x + 5y = –7 4x – 3y = 12
2x – 6y = 5
x – 4y = –8
Graphing Linear Equations From Standard Form It only takes two points to make a line. We can use an
equation in standard form Ax + By = C to find the x-intercept (x, 0) and the y-intercept (0, y).
To find the x-intercept of a line (place where the line crosses the x-axis), simply plug in 0 for y into equation
and solve for x. To find the y-intercept of a line (place where the line crosses the y-axis), let x = 0 and solve
for y. Locate and plot the x- and y-intercepts on your graph than draw a line through the two points.
(NOTE: It really only makes sense to use this method of graphing if the numbers from an equation in Standard Form
will work nicely. Otherwise, we may use another approach, like plotting a point & counting out the slope…)
Let's use the intercept method to graph the following lines:
1) 2x + 5y = 20
2)
3x – 7y = 21
3) x = 6
4) y = 2
Homework for Section 2-2b:
Graphing lines using x-intercept and y-intercept.
Name__________________ Date_____
Use the intercept method to graph the following lines:
1) 3x + 4y = 24
2) 4x + 9y = –36
4) 3x – y = 6
7) x = 8
5)
8)
5x – 3y = –30
y = –5
3) 3x – 8y = 24
6)
2x + y = 8
9) y = 4