Could someone solve this for me please?

I haven't got an idea how to solve this, therefore

please provide answer and show step-by-step would be really appreciated..

Thank you.

a) 2e^(7x)/e^(5x) dx

b)x^2 sqrt (7-3x^3) dx

c) x^3 sqrt ( x-3) dx

Thank you! I don't need an explanation, I'll try to find out by my self,

therefore please get me easy working + answer :)

Thanks