(Sqrt(a/x))*a

√(a/x) · a     --->     √(a/x) · a  =  √a / √x · a

If you want, you can rationalize the denominator by multiplying both the numerator and denominator by √x:

--->      ( √a / √x · a )  · ( √x / √x )  =  √(ax) / x · a  =  a√(ax)/x