Study Guide: Slope-Intercept Form

These web-based activities were developed, during summer sessions from 1997 through 1999, by students at Mainland High School, located in Daytona Beach, FL. As part of Mainland's CCTT grant, the students were given permission by the book's publisher to convert the ancillary materials of the County's adopted Algebra 1 textbook (Glencoe Algebra 1 — ISBN: 9780028253282) into html format.

Study Guide
Writing Linear Equations in Slope-Intercept Form

The x-coordinate of the point where a line crosses the x-axis is called the x-intercept. Similarly, the y-coordinate of the point where the line crosses the y-axis is called the y-intercept.

If an equation is given in standard form Ax + By = C and B ≠ 0 then

the slope of the line (if B ≠ 0) is	− A B
the y-intercept of the line (if B ≠ 0) is	C B
the x-intercept of the line (if A ≠ 0) is	C A

Example 1: Find the x- and y-intercepts of the graph 5x −2y = 10. Then write the equation in slope-intercept form.

Thus, the x-intercept is 2, and the y-intercept is −5. The equation of the line in slope-intercept form is y = ⁵/₂x − 5

Example 2: Find the equation of a line given that it has a slope of 3 and passes through the point (−6, 4).

First, substitute the coordinates of the point into the general slope-intercept form and solve for b

y = mx + b

4 = 3(−6) + b

4 = −18 + b

b = 22

Thus the equation of the line in slope-intercept form will be y = 3x + 22