$5\left(9\right)\left(\frac{3}{5}\right)$

$\left(3\sqrt{x}\right)^2$

$x^2-\left(x+1\right)^2=2x-x^2$

$4x^4-12x^3+8x^2y$

$\int_0^{\frac{3\pi}{2}}\left(\sin\left(\frac{2}{3}x\right)\right)dx$

$\frac{10x^2-3x^3+11x+6}{x+2}$

$\int_0^{\infty}\frac{2x}{\left(1+x^2\right)^2}dx$