Question
Solve each absolute value inequality. Graph the solution
Hint:
|x| is known as the absolute value of x. It is the non-negative value of x irrespective of its sign. The value of absolute value of x is given by
First, we simplify the inequality and then solve it by considering the two cases. Then we plot the graph on the x- axis, or the real line R in such a way that the graph satisfies the value of x from both the cases.
The correct answer is: Combining the above two solutions, we get x ≤ - 4 and x ≥ 4
Step by step solution:
The given inequality is
2|4x|-7 ≥ 25
Adding 7 both sides, we get
2|4x| ≥ 25 + 7
Dividing by 2 throughout, we get
We use the definition of , which is
For, 4x < 0,
We have
|4x|= - 4x ≥ 16
Dividing by 4 throughout, we get
Multiplying on both sides, we have
X ≤ - 4
For, 4x ≥ 0,
We have
|4x|= 4x ≥ 16
Dividing by 4 throughout, we get
Combining the above two solutions, we get
We plot the above inequality on the real line.
The points -4 and 4 are included in the graph.
Adding 7 both sides, we get
Dividing by 2 throughout, we get
We use the definition of , which is
We have
Dividing by 4 throughout, we get
Multiplying on both sides, we have
We have
Dividing by 4 throughout, we get
Combining the above two solutions, we get
We plot the above inequality on the real line.
The points -4 and 4 are included in the graph.
The given inequality contains only one variable. So, the graph is plotted on one dimension, which is the real line. Geometrically, the absolute value of a number may be considered as its distance from zero regardless of its direction. We could also simplify the inequality further before solving it by dividing by 4 throughout.