High School

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 are given the function
[tex]$$
f(x) = 4|x-5| + 3
$$[/tex]
and we need to find the values of [tex]$x$[/tex] for which [tex]$f(x) = 15$[/tex]. Follow these steps:

1. Write the equation:
[tex]$$
4|x-5| + 3 = 15.
$$[/tex]

2. Subtract [tex]$3$[/tex] from both sides to isolate the absolute value term:
[tex]$$
4|x-5| = 15 - 3 = 12.
$$[/tex]

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

4. Solve the absolute value equation:

The equation [tex]$|x-5| = 3$[/tex] means that either:
[tex]$$
x - 5 = 3 \quad \text{or} \quad x - 5 = -3.
$$[/tex]

For [tex]$x-5 = 3$[/tex]:
[tex]$$
x = 5 + 3 = 8.
$$[/tex]

For [tex]$x-5 = -3$[/tex]:
[tex]$$
x = 5 - 3 = 2.
$$[/tex]

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