Parallel and Perpendicular Lines
Are these lines parallel, perpendicular, or neither?
y=2x-5
y=2x+6
Parallel
Graph the line y=2.
Horizontal line with a y-intercept at 2.
Rewrite this equation into slope-intercept form.
y-3=4(x+5)
y=4x+23
Write the x-intercept and y-intercept for this equation.
3x+4y=36
x-intercept: 12
y-intercept: 9
Find the slope of these two points.
(1, -5), (3, -4)
1/2
Are these lines parallel, perpendicular, or neither?
y=2/3x-5
y=-3/2x+6
Perpendicular
Graph the line x=4.
Vertical line with x-intercept of 4.
Rewrite this equation into slope-intercept form.
y+5=1/2(x-6)
y=1/2x-8
Write the x-intercept and y-intercept for this equation.
2x-6y=18
x-intercept: 9
y-intercept: -3
Find the slope of these two points.
(5, 6), (8, 13)
7/3
Are these lines parallel, perpendicular, or neither?
y=4x-5
y=7x+6
Neither
Graph the line y=-7.
Horizontal line with y-intercept of -7.
Rewrite this equation into standard form.
y=-1/2x+2
1/2x+y=2
Write the x-intercept and y-intercept for this equation.
9x+y=27
x-intercept: 3
y-intercept: 27
Find the slope of these two points.
(-15, 9), (0, 3)
-2/5
Are these lines parallel, perpendicular, or neither?
y+7=-2(x-5)
y-5=1/2(x+6)
Perpendicular
Graph the line x=-3.
Vertical line with x-intercept at -3.
Rewrite this equation into standard form.
y=-7/5x-3
7/5c+y=-3
Write the x-intercept and y-intercept for this equation.
-5x+8y=-40
x-intercept: 8
y-intercept: -5
Find the slope of these two points.
(10, 17), (7, 8)
3
Are these lines parallel, perpendicular, or neither?
y-2=3/4(x+1)
y+3=3/4(x+8)
Parallel
What is the slope of a horizontal line?
What is the slope of a vertical line?
Horizontal lines have a slope of 0.
Vertical lines have an undefined slope.
Rewrite this equation into standard form.
y+5=-3(x-2)
3x+y=1
Write the x-intercept and y-intercept for this equation.
-6x-2y=-18
x-intercept: 3
y-intercept: -9
Find the slope of these two points.
(12, -3), (-17, 3)
-6/29