Download View Writing Linear Equations using Slope

Writing Linear Equations
Slope – Intercept form
Review: Slope Formula
y2  y1
m
x2  x1
Review: X and Y- intercepts
• The x-intercept of a graph is the point where the
graph crosses the x-axis.
• The y-intercept of a graph is the point where the
graph crosses the y-axis.
• Example: x-intercept = (3, 0)
y-intercept = (0, 1)
Slope – Intercept Form
y = mx + b
m represents the slope
b represents the y-intercept
To find the slope and y-intercept of
an equation, write the equation in
slope-intercept form: y = mx + b.
Find the slope and y-intercept.
1) y = 3x – 7
y = mx + b
Find the slope and y-intercept.
2
2) y = x
3
y = mx + b
2
y= x+0
3
3) y = 5
y = mx + b
y = 0x + 5
Find the slope and y-intercept.
4)
5x - 3y = 6
Find the slope and y-intercept.
5) 2y + 2 = 4x
Find the slope and y-intercept of
y = -2x + 4
Writing Equations
When asked to write an equation, you
need to know two things – slope (m)
and y-intercept (b).
There are three types of problems you
will face.
Step 1 – find m
Step 2 – find b
Step 3 – write the equation
Writing Equations – Type #1
Write an equation in slope-intercept form of the
line that has a slope of 2 and a y-intercept of 6.
EXAMPLE
• Write an equation in slope-intercept form of
the line that has a slope of -3 and a yintercept of -4.
Write the equation of a line that has
a y-intercept of -3 and a slope of -4.
Writing Equations – Type #2
Write an equation of the line that has a slope of 3
and goes through the point (2,1).
EXAMPLE
• Write an equation of the line that has a slope
of -2 and goes through the point (3,-4).
Writing Equations – Type #3
Write an equation of the line that goes through the
points (-2, 1) and (4, 2).
Writing Equations – Type #3
EXAMPLE
• Write an equation of the line that goes through
the points (-2, 5) and (4, 8).
Write an equation of the line that goes
through the points (0, 1) and (1, 4).