Nursing Preparation Study Guide

Nursing Preparation Study Guide represents the y-intercept or the point where the line touches the y-axis. The graphs of linear equations will always be a solid straight line. To determine how to graph a linear equation you can make a table from the equation. Choose values of x , substitute them into the equation, and solve for y . These x and y values will be used to make the ordered pairs. Next, plot these ordered pairs on the coordinate plane and then connect your dots. Remember a line will extend infinitely at both end points. Example Graph = −2 + 4 = −2 + 4 Ordered Pair 0 = −2(0) + 4 = 0 + 4 = 4 4 (0,4) 1 = −2(1) + 4 = −2 + 4 = 2 2 (1,2) 2 = −2(2) + 4 = −4 + 4 = 0 0 (2,0) 3 = −2(3) + 4 = −6 + 4 = −2 −2 (3, −2) To write the equation of a line from a graph, begin by identifying the slope and y -intercept of the line. Next substitute these values into the slope-intercept equation. Example Write an equation of the line from the graph. Step 1: Find the slope = 8 − < 8 − < = 1 − (−3) 2 − 0 = 1 + 3 2 = 4 2 = 2 Step 2: Find the y -intercept. Recall that the y-intercept is the location where the equation touches the y-axis. This always occurs at (0, ) . From the graph we can see that the y-intercept is at −3 . Therefore = −3 . Step 3: Make the substitutions into the equation. = + = 2 − 3

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