Because \(x \geq a\), \(|x-a| = x-a \)
\((x-a) + (100-x) + |x-a-50| = 100 |x-a-50| = a = f(x)\)
The graph indicates that when \(x=a, a= 50\) and \(|x-a-50|=a.\)
Likewise, if \(x=a+100\), then \(|x-a-50|=a,\) and \(a= 50.\)
Thus, when\( f(x) = 100\), the value of \(a = 50. \)