SOLUTION

1
Write an equation of a parallel line
EXAMPLE 1
Write an equation of the line that passes through
(3,5) and is parallel to the line y 3x 1.
SOLUTION
STEP 1
Identify the slope. The graph of the given
equation has a slope of 3. So, the parallel line
through ( 3, 5) has a slope of 3.
STEP 2
Find the y-intercept. Use the slope and the given
point.
2
Write an equation of a parallel line
EXAMPLE 1
y mx b
Write slope-intercept form.
5 3( 3) b
Substitute 3 for m, 23 for x, and 25 for y.
Solve for b.
4 b
STEP 3
Write an equation. Use y mx b.
Substitute 3 for m and 4 for b.
y 3x 4
3
for Example 1
GUIDED PRACTICE
SOLUTION
STEP 1
Identify the slope. The graph of the given
equation has a slope of 1.So, the parallel line
through ( 2, 11) has a slope of 1.
STEP 2
Find the y-intercept. Use the slope and the given
point.
4
for Example 1
GUIDED PRACTICE
y mx b
Write slope-intercept form.
11 (1 )( 2) b
Substitute 11 for y, 1 for m, and 2 for x.
Solve for b.
9 b
STEP 3
Write an equation. Use y m x b.
y x 9
Substitute 1 for m and 9 for b.