b a？ 3=24, so a? =4 and a > 0, so a=2 and b=3.

The function is f(x)=3×2? x

( 1/2)? x+( 1/3)？ X-m≥0, which holds. ( 1/2)? x>0，( 1/3)？ x>0

So -m≥0 and m≤0 is enough.