Definite Integral of x^2*sqrt(7x+9) from 0 to 1 - Need Help!

[mckallin]

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)

 

[Rainbow Child]

Try the substitution

\sqrt{7x+9}=y

 

[mckallin]

sorry, I still can't figure out it, can you give me some more detail? thanks a lot .

 

[HallsofIvy]

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.)

 

[mckallin]

I got it, thanks for help! ^-^