# Definite Integral [help] !!!

by mckallin
Tags: definite, integral
 P: 15 hello, can anyone help me how to complete the following definite integral? Thanks!! ∫ (x^2)*sqrt(7 x + 9) dx (From 0 to 1)
 P: 365 Try the substitution $$\sqrt{7x+9}=y$$
 P: 15 sorry, I still can't figure out it, can you give me some more detail? thanks a lot .
Math
Emeritus
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.)