Answer
$ 1.6(3x-4)^{3/2}+C$
Work Step by Step
see Substitution RuIe, p.962:
(1)
let $u=3x-4$
(2)
$du=3dx\displaystyle \ \ \Rightarrow\ \ dx=\frac{du}{3}$
$(3)$
$\displaystyle \int 7.2(3x-4)^{1/2}dx=\int 7.2u^{1.2}(\frac{du}{3})$
... constant multiple, power rules
$=\displaystyle \frac{7.2}{3}\cdot\frac{u^{3/2}}{\frac{3}{2}}+C$= ... bring back x
$=\displaystyle \frac{2.4\cdot 2}{3}(3x-4)^{3/2}+C$
$=1.6(3x-4)^{3/2}+C$
