$\frac{9^2}{4}+ab+b^2$

$\int\left(2x+4\right)\left(x^2+4x+5\right)dx$

$ln\:\left(\frac{e^{tanx}}{y}\right)=x$

$\int_{\pi}^{\frac{3\pi}{2}}\left(\frac{sino}{2+coso}\right)do$

$\lim_{x\to\infty}\left(\frac{x^2+1}{x\ln\left(x\right)}\right)$

$\int\left(\frac{x-4}{x^2}\right)dx$

$1b$