Question #6408461Single Choice
Algebra-1
Question
Solve 3 |2x + 7| - 7 < -4
Options
A
x < -3 and x >
B
x < -3 and x > -4
C
all real numbers
D
no solution
Answer & Analysis
Answer
B
Analysis
To solve the inequality 3 |2x + 7| - 7 < -4, we can begin by adding 7 to both sides:
3 |2x + 7| < 3
Next, we can divide both sides of the inequality by 3:
|2x + 7| < 1
Now, we can break it down into two cases:
Case 1: 2x + 7 is nonnegative (i.e., 2x + 7 ≥ 0)
In this case, the absolute value |2x + 7| is equal to 2x + 7, so we have:
2x + 7 < 1
Solving this inequality, we get:
2x < 1 - 7
2x < -6
Dividing both sides of the inequality by 2, we have:
x < -3
Case 2: 2x + 7 is negative (i.e., 2x + 7 < 0)
In this case, the absolute value |2x + 7| is equal to -(2x + 7), so we have:
-(2x + 7) < 1
Simplifying this inequality, we get:
-2x - 7 < 1
Adding 7 to both sides of the inequality, we have:
-2x < 1 + 7
-2x < 8
Dividing both sides of the inequality by -2 reverses the inequality sign:
x > -4
So the solution to the inequality 3 |2x + 7| - 7 < -4 is:
x < -3 and x > -4
Comparing the solution to the given answer choices:
A. x < -3 and x >
3 |2x + 7| < 3
Next, we can divide both sides of the inequality by 3:
|2x + 7| < 1
Now, we can break it down into two cases:
Case 1: 2x + 7 is nonnegative (i.e., 2x + 7 ≥ 0)
In this case, the absolute value |2x + 7| is equal to 2x + 7, so we have:
2x + 7 < 1
Solving this inequality, we get:
2x < 1 - 7
2x < -6
Dividing both sides of the inequality by 2, we have:
x < -3
Case 2: 2x + 7 is negative (i.e., 2x + 7 < 0)
In this case, the absolute value |2x + 7| is equal to -(2x + 7), so we have:
-(2x + 7) < 1
Simplifying this inequality, we get:
-2x - 7 < 1
Adding 7 to both sides of the inequality, we have:
-2x < 1 + 7
-2x < 8
Dividing both sides of the inequality by -2 reverses the inequality sign:
x > -4
So the solution to the inequality 3 |2x + 7| - 7 < -4 is:
x < -3 and x > -4
Comparing the solution to the given answer choices:
A. x < -3 and x >
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