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Exercises Graphs and straight lines

Example 4.40 from Elementary Algebra, 4.5 Use the Slope–Intercept Form of an Equation of a Line

Use the Slope–Intercept Form of an Equation of a Line: example 4.40

Use the graph to find the slope and y-intercept of the line, $y = 2 x + 1$ .

Compare these values to the equation $y = m x + b$ .

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
To find the slope of the line, we need to choose two points on the line. We’ll use the points $(0, 1)$ and $(1, 3)$ .

Find the rise and run.

Find the y-intercept of the line. The y-intercept is the point (0, 1).

The slope is the same as the coefficient of $x$ and the y-coordinate of the y-intercept is the same as the constant term.

Your turn

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

Use the graph to find the slope and y-intercept of the line $y = \frac{2}{3} x - 1$ . Compare these values to the equation $y = m x + b$ .

The figure shows a line graphed on the x y-coordinate plane. The x-axis of the plane runs from negative 8 to 8. The y-axis of the plane runs from negative 8 to 8. The line goes through the points (0, negative 1) and (6, 3).

How did it go?

PreviousUnderstand Slope of a Line: example 4.39 Next Use the Slope–Intercept Form of an Equation of a Line: example 4.41

From Elementary Algebra (1st edition) by OpenStax (Rice University), section 4.5, 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.