Given the function f(x)=4|x-5|+3 for what values of x is f(x)=15

  {2, 8}

Step-by-step explanation:

We want to find x for ...

  15 = 4|x -5| +3

  12 = 4|x -5| . . . . subtract 3

  3 = |x -5| . . . . . . divide by 4

  ±3 = x -5 . . . . . . show the meaning of absolute value

  5 ±3 = x = {2, 8} . . . . . add 5

The values of x for which f(x) = 15 are 2 and 8.