$1-8$ Evaluate the integral by making the given substitution.

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}cos2xdx,u=2x$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}x{e}^{-x^2}dx,u=-x^2$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}{x}^2\sqrt[\phantom{2}]{x^3+1}dx,u=x^3+1$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}si{n}^{2}cosd,u=sin$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{x^3}{x^4-5}dx,u=x^4-5$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{1}{x^2}\sqrt[\phantom{2}]{1+\frac{1}{x}}dx,u=1+\frac{1}{x}$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}\frac{cos\sqrt[\phantom{2}]{t}}{\sqrt[\phantom{2}]{t}}dt,u=\sqrt[\phantom{2}]{t}$

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}z\sqrt[\phantom{2}]{z-1}dz,u=z-1$

NUMBERS $5$ AND $7$ ONLY