Use the formula

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\sqrt[\phantom{2}]{u^2-a^2}du=\frac{u}{2}\sqrt[\phantom{2}]{u^2-a^2}-\frac{a^2}{2}ln(|u\sqrt[\phantom{2}]{u^2-a^2}|)C$

to evaluate the following integral. $($Use $C$ for the constant of integration.$)$

${\displaystyle \underset{1}{\overset{2}{}}}7\sqrt[\phantom{2}]{4x^2-3}dx$