3.5 Write and Graph Equations of Lines
Slope-intercept form: y = mx + b
m = slope
b = y-intercept
10
Ex 1: Write an equation for the line in slope intercept form:
8
6
4
2
-5
-2
Ex 2: Write the equation of the line given: m = -1/2 and b = 4
Ex 3: Write the equation of the line given the point P and the slope m.
a.) P (1, –3)
m = 1/3
b.) P (4, 5)
m = –2
Ex 4: Write an equation for the line passing through point (-1,1) that is:
a) parallel to the line y = 2x -3
b) perpendicular to the line y = 2x - 3
−A
B
When in this form, it is often easier to graph using the intercepts.
To find: x-intercepts (Let y = 0) and y-intercepts (Let x = 0).
Standard Form: Ax + By = C
Slope =
Graph 8x − 2y = 10
Ex 5: Graph 3x + 4y = 12
8
8
6
6
4
4
2
2
-5
5
-5
5
-2
-2
-4
-4
-6
-6
-8
-8