# Definite Integral [help]

by mckallin
Tags: definite, integral
 P: 365 Try the substitution $$\sqrt{7x+9}=y$$
 Math Emeritus Sci Advisor Thanks PF Gold P: 39,339 Definite Integral [help] 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.)