Step-by-step explanation:
Given that [tex]f(x)=4|x-5|+3[/tex]
We need the values of [tex]x[/tex] for which [tex]f(x)=15[/tex].
So,
[tex]15=4|x-5|+3[/tex]
[tex]12=4|x-5|[/tex]
[tex]|x-5|=3[/tex]
If [tex]x\geq 5,[/tex]
[tex]x-5=3\\x=8[/tex]
If [tex]x< 5,[/tex]
[tex]5-x=3\\x=2[/tex]
So,[tex]2,8[/tex] are the solutions