## Definite Integral [help] !!!

hello, can anyone help me how to complete the following definite integral? Thanks!!
∫ (x^2)*sqrt(7 x + 9) dx (From 0 to 1)
 Try the substitution $$\sqrt{7x+9}=y$$
 sorry, I still can't figure out it, can you give me some more detail? thanks a lot .

Recognitions:
Gold Member
If $y= \sqrt{7x+ 9}$, what is dx (in terms of dy and y)? What is x in terms of y? (So you can substitute for that x2.)