1. Different ways to write equations of lines
Slope-intercept form
y = mx + b
slope = –2
y-intercept: 5
y = –2x + 5

2. Different ways to write equations of lines
Point-slope form
y – y1 = m(x – x1)
point: (4, –3)
slope = –2
y – (–3) = –2(x – 4)

3. Are they the same???
Slope-Intercept form
y = –2x + 5
Point-slope form
y – (–3) = –2(x – 4)
y + 3 = –2x + 8
-3 -3
y = –2x + 5

4. Write the point-slope form of an equation for a line that
passes through (4, –3) with slope –2.
Write the equation in slope-intercept form
y + 3 = –2x + 8
-3 -3
y = –2x + 5
point-slope form
slope-intercept form
x1 y1 m
y = mx + b

5. Write the point-slope form of an equation for a line that
passes through (3, 5) with slope .
Write the equation in slope-intercept form
+5 +5
y = x + 1
point-slope form
slope-intercept form
x1 y1
y = mx + b

6. Different ways to write equations of lines
Standard form
Ax + By = C
•no fractions in equation
•x and y terms are on the left side
Example: 5x + 2y = 10 is in standard
form

7. Write in standard form.
standard form
Ax + By = C

8. Write in standard form.
standard form:
Ax + By = C
y – 3 = 2x + 8
+3 +3
y = 2x + 11 slope-intercept
form:
y = mx + b
point-slope form:
y – y1 = m(x – x1)
-2x -2x
-2x + y = 11