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Exercises Graphs and straight lines

Example 4.58 from Elementary Algebra, 4.6 Find the Equation of a Line

Find the Equation of a Line: example 4.58

Find the equation of the line shown.

The graph shows the x y-coordinate plane. The x and y-axes each run from negative 7 to 7. A line intercepts the y-axis at (0, negative 4), passes through the plotted point (3, negative 2), and intercepts the x-axis at (4, 0).

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Solution
We need to find the slope and y-intercept of the line from the graph so we can substitute the needed values into the slope–intercept form, $y = m x + b$ .

To find the slope, we choose two points on the graph.

The y-intercept is $(0, −4)$ and the graph passes through $(3, −2)$ .

Find the slope by counting the rise and run.

Find the y-intercept.

Substitute the values into $y = m x + b .$

Your turn

The book's Try It right after this example: same idea, new numbers. Only the answer is given.

Find the equation of the line shown in the graph.

The graph shows the x y-coordinate plane. The x and y-axes each run from negative 7 to 7. A line intercepts the x-axis at (negative 2, 0), intercepts the y-axis at (0, 1) and passes through the plotted point (5, 4).

How did it go?

PreviousFind the Equation of a Line: example 4.57 Next Find the Equation of a Line: example 4.59

From Elementary Algebra (1st edition) by OpenStax (Rice University), section 4.6, licensed under CC BY 4.0. Original at openstax.org. We split the solution into steps; the words, numbers and figures are the book's. OpenStax doesn't endorse this site.