High School

Solve [tex]4|x+5|=28[/tex].

A. [tex]x=12[/tex] and [tex]x=-2[/tex]

B. [tex]x=-12[/tex] and [tex]x=-2[/tex]

C. [tex]x=-12[/tex] and [tex]x=2[/tex]

D. [tex]x=12[/tex] and [tex]x=-12[/tex]

Answer :

To solve the equation [tex]\(4|x+5|=28\)[/tex], let's break it down into a series of steps:

1. Isolate the absolute value expression:
[tex]\[
4|x+5| = 28
\][/tex]
Divide both sides by 4:
[tex]\[
|x+5| = 7
\][/tex]

2. Solve the absolute value equation:
The equation [tex]\( |x+5| = 7 \)[/tex] means that [tex]\( x+5 \)[/tex] can be either 7 or -7. This gives us two separate cases to solve:

- Case 1:
[tex]\[
x + 5 = 7
\][/tex]
Subtract 5 from both sides:
[tex]\[
x = 2
\][/tex]

- Case 2:
[tex]\[
x + 5 = -7
\][/tex]
Subtract 5 from both sides:
[tex]\[
x = -12
\][/tex]

3. Check the solutions:

- For [tex]\( x = 2 \)[/tex]:
[tex]\[
4|2 + 5| = 4 \cdot 7 = 28
\][/tex]
This is a valid solution.

- For [tex]\( x = -12 \)[/tex]:
[tex]\[
4|-12 + 5| = 4 |-7| = 4 \cdot 7 = 28
\][/tex]
This is also a valid solution.

Therefore, the solutions to the equation [tex]\( 4|x+5| = 28 \)[/tex] are [tex]\( x = 2 \)[/tex] and [tex]\( x = -12 \)[/tex].

The correct answer is:
C. [tex]\( x = -12 \)[/tex] and [tex]\( x = 2 \)[/tex]