$\int x\left(-\frac{1}{e^x}-9e^{-9x}\right)dx$

$4\ln\left(2\right)+\ln\left(x-1\right)=\ln\left(48\right)$

$\int_2^5sec^3\left(t\right)dt$

$3a^5-2a^4-8a^3$

$\int3xtan^{-1}\left(x\right)dx$

$\lim_{x\to4}\left(3x+1\right)$

$\lim_{x\to-\infty}\left(\frac{3^x+5^x}{7^x+5^x}\right)$