$\int\frac{3x^2+x-1}{\left(x^2-5x+6\right)}dx$

$\int_1^4\left(\frac{1}{4}e^{\frac{-t}{4}}\right)dx$

$f\left(x\right)=\frac{\left(x+1\right)^2\left(x+3\right)^3}{x^2-2x-3}$

$\lim_{x\to0}\frac{1}{\sin\left(x\right)}-\frac{1}{x}$

$\left(-23\right)\cdot\left(-5\right)+\left(-23\right)\cdot\left(+19\right)$

$-2\:\left(\frac{3}{8\:}\:a\:\:-\:\frac{5}{9}\:b\:\right)\:+\left\{-\:\frac{2}{3\:}\:a\:\:-3\:\left(\:-\frac{5}{3\:}\:a\:+\:\frac{7}{18}\:b\:\right)+\:\frac{1}{3}\:b\right\}$

$\left(-\sqrt{9}\:+\:\sqrt[3]{-27}\right)^2$