the product of the values of a for which |5a-4|=a is true is

\(|5a-4|=a \Rightarrow (5a-4)=a \text{ or }4-5a=a\\ 5a-4=a\\ 4a=4\\ a=1\\ \\ 4-5a=a\\ 4=6a\\ a = \dfrac 2 3\\ 1 \cdot \dfrac 2 3 = \dfrac 2 3\)

.