Which of the following graphs shows the solution set for the inequality below?
3|x + 1| < 9

Answer:
Graph D
Step-by-step explanation:
3|x + 1| < 9
divide both sides by 3:
(3|x + 1|)/3 < 9/3
|x + 1| < 3
so:
x + 1 < 3 OR x + 1 > -3
first equation: x + 1 < 3
x + 1 < 3
subtract 1 from both sides:
x + 1 - 1 < 3 - 1
x < 2
(-∞,2)
Second equation: x + 1 > -3
x + 1 < -3
subtract 1 from both sides:
x + 1 -1 > -3 - 1
x > -4
(-4,∞)
You are to graph: (-4,∞) ∩ (-4,∞)
this is Graph D.
Answer:
Graph D
Step-by-step explanation:
Given inequality:
[tex]3|x+1| < 9[/tex]
Divide both sides by 3:
[tex]\implies |x+1| < 3[/tex]
[tex]\textsf{Apply the absolute rule: \quad If $|u| < a$ when $a > 0$, then $-a < u < a$}[/tex]
[tex]\begin{aligned} \underline{\sf Case\; 1} && \underline{\sf Case\; 2}\\-3& < x+1 & \quad \quad \quad x+1& < 3\\-4& < x & x& < 2\end{aligned}[/tex]
Therefore, the solution set for the given inequality is:
[tex]\{x|-4 < x < 2\}[/tex]
When graphing inequalities on a number line:
Place an open circle at x = -4 and x = 2.
Shade between the two values.