Writing Linear Equations Slope – Intercept form

Review: Slope Formula

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)

b represents the y-intercept 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. y = 3x – 7 y = mx + b

Find the slope and y-intercept. 2) y = x y = mx + b y = x + 0 3) y = 5 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 y-intercept 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).