be f and g Functions are Defined for any X.

is it Known that 2f(x)-3g(x) and 5f(x)+4g(x) are Derivative in X0.

prove that the product f(x)g(x) are Derivative in X0.

thanks

Try using the product rule.

\frac{d}{dx}[f(x)g(x)]=f(x)g'(x)+g(x)f'(x)

well I know the rule that say's if f is Derivative and g Derivative so f*g also Derivative
but I don't know how to do it here because what is the Differential for example 5f(x)? And they ask me about f and g. here I got factor before the f and g.

thnaks

If I am understanding your explanation of the problem correctly, 2f(x)-3g(x) is a derivative of f(x)g(x).

Then, f(x)g'(x)+g(x)f'(x)=2f(x)-3g(x).

The same for the other.

Hi thanks for help I know how to keep from here :)