Slope-Intercept Form of a Linear Equation

Is this a linear equation? 3x + 2y = 6

Let’s Graph!  How would you graph the first equation?  How would you graph the second equation?

A linear equation in the form of y = mx + b is in slope-intercept form. When a linear equation is solved for y, you can identify the slope and the y-intercept.

Examples:  Write an equation of the line whose slope is and whose y-intercept is -6.  Let m = slope and b = y-intercept.  y = x – 6

 Write an equation of the line shown in the graph.

Writing Equations in Slope- Intercept Form  4x – 6y = 3 Find the slope and y-intercept.  12x = -3y + 24 Find the slope and y-intercept

 Recall that Ax + By = C is the standard form of a linear equation. Solve this equation for y.  Write 8x – 4y = 12 in slope-intercept form.

Graphing Linear Equations  Set up a table of values.  Quick graphs using intercepts (standard form)  Slope and y-intercept  Graph y = 0.5x – 7  Graph 5x + 4y = 8

Real Life Examples of Slope- Intercept Form  Plumber A charges a flat rate of $25 plus $30 an hour  Define the variables and write an equation for Plumber A  Plumber B charges a flat rate of $40 plus $25 an hour.  Define the variables and write an equation for Plumber B  Graph both equations.