Big Ideas Math Algebra 1, 2015
BI
Big Ideas Math Algebra 1, 2015 View details
1. Writing Equations in Slope-Intercept Form
Continue to next subchapter

Exercise 44 Page 180

Substitute 0 for one variable and solve. Then, repeat for the other and graph.

Practice makes perfect

We will graph this equation by finding and plotting its intercepts. Then, we will connect them with a line. To find the x- and y-intercepts, we will need to substitute 0 for one variable and solve. After that, repeat for the other variable.

Finding the x-intercept

Think of the point where the graph of an equation crosses the x-axis. The y-value of that ( x, y) coordinate pair is equal to 0, and the x-value is the x-intercept. To find the x-intercept of the given equation, we should substitute 0 for y. Then, solve for x.
x-6y=24
x-6( 0)=24
x=24

An x-intercept of 24 means that the graph passes through the x-axis at the point ( 24,0).

Finding the y-intercept

Let's use the same concept to find the y-intercept. Consider the point where the graph of the equation crosses the y-axis. The x-value of the ( x, y) coordinate pair at the y-intercept is 0. Therefore, substituting 0 for x will give us the y-intercept.
x-6y=24
0-6y=24
-6y=24
y=-4
A y-intercept of - 4 means that the graph passes through the y-axis at the point (0, - 4).

Graphing the Equation

We can now graph the equation by plotting the intercepts and connecting them with a line.