LINEAR FUNCTIONS Solving Linear Inequalities (Page 4 of 4)

Let's use TRACE to identify where these values of x are. Since the y-values of the two functions are equal at the intersection point, the x-values we want must be either to the left or to the right of this point. While in TRACE, use the up arrow or down arrow keys to move back and forth between the graphs. Do this at several places on each side of the intersection point and compare the Y1 and Y2 y-values.

 TRACE key.

 Left arrow key.... Up arrow key. or Down arrow key.
 Right arrow key.... Up arrow key. or Down arrow key.

Calculator screen image. Calculator screen image.

The x-values to the right of -1.75 produce y-values for Y1 that are greater than those of Y2. The inequality 3x+4 > (1/3)(x-2) means that the graph of Y1 must lie above the graph of Y2. Looking at the graphs, we see this is true if x is to the right of the intersection point, meaning to the right of -1.75. So, the solution set is {x: x > -1.75}, or in interval notation, (-1.75, infinity).

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