High School

Solve [tex]$4|x+5|=16$[/tex].

A. [tex]$x=1$[/tex] and [tex]$x=-1$[/tex]
B. [tex]$x=1$[/tex] and [tex]$x=-9$[/tex]
C. [tex]$x=-1$[/tex] and [tex]$x=-9$[/tex]
D. [tex]$x=-1$[/tex] and [tex]$x=9$[/tex]

Answer :

To solve the equation [tex]\(4|x+5|=16\)[/tex], let's break down the steps involved:

1. Simplify the equation:
- Divide both sides by 4 to isolate the absolute value:
[tex]\[
|x + 5| = 4
\][/tex]

2. Consider the two cases for the absolute value:
- The expression [tex]\(|x+5|\)[/tex] means that [tex]\(x+5\)[/tex] can be either 4 or [tex]\(-4\)[/tex]. This is because the absolute value of a number is its distance from zero on a number line, and it can be obtained in two ways: one positive, one negative.

3. Case 1: [tex]\(x + 5 = 4\)[/tex]
- Solve for [tex]\(x\)[/tex]:
[tex]\[
x + 5 = 4
\][/tex]
Subtract 5 from both sides:
[tex]\[
x = 4 - 5
\][/tex]
[tex]\[
x = -1
\][/tex]

4. Case 2: [tex]\(x + 5 = -4\)[/tex]
- Solve for [tex]\(x\)[/tex]:
[tex]\[
x + 5 = -4
\][/tex]
Subtract 5 from both sides:
[tex]\[
x = -4 - 5
\][/tex]
[tex]\[
x = -9
\][/tex]

Thus, the solutions are [tex]\(x = -1\)[/tex] and [tex]\(x = -9\)[/tex].

Therefore, the correct answer is:
C. [tex]\(x = -1\)[/tex] and [tex]\(x = -9\)[/tex]