$\int x ^ { - 45 } d x$

$\lim_{x\to\frac{1}{4}}\left(e^{\frac{ln\left(tan2\pi x\right)}{\frac{1}{1-4x}}}\right)$

$-8-\left(5-1\right)$

$10.000\cdot\:0.001\cdot\:100$

$2.450-327$

$1-\left(5-3+2\right)-\left|5-\left(6-3+1-2\right)\right|$

$\lim_{x\to0}\left(\frac{6x^2}{secx-1}\right)$