College

Given the function [tex]f(x)=4|x-5|+3[/tex], for what values of [tex]x[/tex] is [tex]f(x)=15[/tex]?

A. [tex]x=2, x=8[/tex]
B. [tex]x=1.5, x=8[/tex]
C. [tex]x=2, x=7.5[/tex]
D. [tex]x=0.5, x=7.5[/tex]

Answer :

We start with the equation
[tex]$$
4|x-5| + 3 = 15.
$$[/tex]

Step 1: Isolate the absolute term

Subtract 3 from both sides to get:
[tex]$$
4|x-5| = 15 - 3 = 12.
$$[/tex]

Step 2: Solve for the absolute value

Divide both sides by 4:
[tex]$$
|x-5| = \frac{12}{4} = 3.
$$[/tex]

Step 3: Solve the absolute value equation

The equation [tex]$|x-5| = 3$[/tex] has two cases:

1. Case 1: When the expression inside the absolute value is positive:
[tex]$$
x-5 = 3 \quad \Longrightarrow \quad x = 5 + 3 = 8.
$$[/tex]

2. Case 2: When the expression inside the absolute value is negative:
[tex]$$
x-5 = -3 \quad \Longrightarrow \quad x = 5 - 3 = 2.
$$[/tex]

Thus, the solutions are [tex]$x = 2$[/tex] and [tex]$x = 8$[/tex].

Final Answer: [tex]$x = 2 \text{ or } x = 8$[/tex].

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