Given the function f (x) = loga (a-ax) (a > 0, and a ≠ 1), find the domain of definition and range of value

Given the function f (x) = loga (a-ax) (a > 0, and a ≠ 1), find the domain of definition and range of value

a> 0 and a ≠ 1, so a-ax > 0