ALGEBRA 1 CC
Graphing and Writing Equations in SlopeIntercept Form
• The three forms of writing a linear equation that we will
cover this week
• Slope-Intercept form
• Standard Form
• Point-Slope Form
y  mx  b
Ax  By  C
y  y1  m  x  x1 
Example 1
• Write an equation of the line shown
Example 2
• Write an equation of the line that passes through the
points (4, -2) and (-2, 2)
Example 3
• Write the equation of the line that passes through the
point (-4, -9) and has a slope of 2.
Graphing a Linear Equation
• Step 1: Rewrite the equation in slope-intercept form (if
necessary).
• Step 2: Identify the slope and y-intercept
• Step 3: Plot the y-intercept
• Step 4: Use the slope to plot a second point and then
draw a line through the two points.
• It is optional, but highly recommended to draw more than
two points to graph a linear equation
Example 4 & 5
• Identify the slope and y-intercept of the line with the given
equations and then graph the equations.
4) y  1 x  4
5) 4x – 3y = 15
2
Example 6
• Write an equation for the linear function f with the given
values
f(6) = -4, f(9) = -9
• Two lines in the same plane are parallel if they
do not intersect.
• Parallel lines have the same slope.
• Two lines in the same plane are perpendicular if
they intersect to form a right angle.
• Perpendicular lines have slopes that are
opposite reciprocals.
Example 7
• Tell whether the following graphs are parallel,
perpendicular, or neither.
y = 2x + 4
4x + 2y = 12
Example 8
• Tell whether the following graphs are parallel,
perpendicular, or neither.
3x + 4y = 24
-4x + 3y = 20