Core Connections Algebra 1, 2013
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Core Connections Algebra 1, 2013 View details
3. Section 10.3
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Exercise 129 Page 512

Graph each inequality separately. The overlapping region will be the solution of the system.

Practice makes perfect

To solve the given system by graphing, we should first draw each inequality separately. Then we will combine the graphs. The overlapping region will be the solution set. Let's start!

Inequality I

To determine the boundary line of the first inequality, we need to exchange the inequality symbol for an equals sign. Inequality:& y ≤ - |x-2|+3 Boundary Line:& y = - |x-2|+3 The graph of this boundary line is the graph of the parent function y=|x| translated right 2 units, reflected in the x-axis, and translated up 3 units. The boundary line will be dashed because the inequality is strict.
Next, we need to decide which side of the boundary line we should shade. We can do this by testing a point that does not lie on the boundary line. If the point satisfies the inequality, it lies in the solution set. If not, we will shade the other region. Let's use (0,0).
y≤ - |x-2|+3
0? ≤| 0-2|+3
â–Ľ
Simplify
0? ≤- |-2|+3
0? ≤- 2+3
0≤ 1
Because (0,0) created a true statement, we will shade the region containing this point.

Inequality II

Now that we have completed the first inequality, let's determine the boundary line of the second inequality. We will follow the same process once more. Inequality:& y ≥ - 1 Boundary Line:& y=- 1 This boundary line is a horizontal line. The inequality y ≥ - 1 describes all values of y that are greater than or equal to - 1. This means that every coordinate pair with a y-value that is greater than or equal to - 1 needs to be included in the shaded region. Notice that the inequality is non-strict, so the boundary line will be solid.

Combining the Inequality Graphs

In drawing the inequality graphs on the same coordinate plane, we are able to see the overlapping section. This is the solution set of the system.

Finally, we can view only the solution set by removing the shaded regions that are not overlapping.