

Slope Intercept FormA way to express the equation of a line
The slope intercept form is probably the most frequently used way to express equation of a line. To be able to use slope intercept form, all that you need to be able to do is 1) find the slope of a line and 2) find the yintercept of a line.
Video Tutorial on Slope Intercept Form
The FormulaIn general, the slope intercept form assumes the formula: y= mx +b.
Examples:
Slope Intercept Equation of vertical and horizontal linesVertical Lines The Equation of a vertical line is x = bSince a vertical line goes straight up and down, its slope is undefined. Also, the x value of every point on a vertical line is the same. Therefore, whatever the x value is, is also the value of 'b'. For instance, the red line in the picture below is the graph of the x = 1.Horizontal Lines The equation of a horizontal line is y = b where b is the yintercept. Since the slope of a horizontal line is 0, the general formula for the standard form equation , y = mx + b becomes y= 0x +b y = b. Also,since the line is horizontal, every point on that line has the exact same y value. This yvalue is therefore also the yintercept. For instance, the red line in the picture below is the graph of the horizontal line y =1. (In depth lesson on the equation of a horizontal line)
What is the slope intercept form of the lines graphed below? Step 1) What is the slope of the line below?
Step 2) What is the yintercept of the line on the left?
2 or the y value of the point (0,2) Step 3) What is the slopeintercept form of this line's equation?
y=mx+b y = 1x + 2 Look at the picture of the graph below. Find the slope of this line, its yintercept, then express the equation of this line in slope intercept form What is the slope of the line on the left?
slope =$$ \frac{rise}{run} = \frac{2}{1} = 2$$ What is the yintercept of the line on the left?
1 which is the y coordinate of the point (0, 1) What is the slope intercept form of this line?
m = slope = 2 b = yintercept of the line = 1 Therefore, the slope intercept form of this line is y = 2x 1 What is the slope intercept form of the line pictured in the graph below?
b= yintercept of the line = 2 Therefore, the equation of this line in slope intercept form is $$y = \frac{1}{2} +2 $$ What is the slope intercept form of the line pictured in the graph below?
Practice Problems Write the slope intercept form for the lines below
Problem 1) A line with a slope of 2 and a yintercept of 12
m = slope = 2 b = the y intercept = 12 The slope intercept form of the equation:
Problem 2) A line with a slope of 3 and a yintercept of 5
m = slope = 3 b = the y intercept = 5 The slope intercept form of the equation:
Problem 3) A line with a slope of ½ and a yintercept of 7
m = slope = ½ b = the y intercept = 7 The slope intercept form of the equation:
Linear Equations: slope of a line  yintercept  interactive linear equation  equation given slope and a point equation from graph of a line  real world applications  images
