$78-5+\left(\frac{34}{\left(18-1\right)}+5\right)-\left(45-4\cdot\left(23-4\cdot5\right)\right)+18$

$\int_0^4\frac{\left(5\right)}{\sqrt{25-x^2}}dx$

$\left(2xy-\sec^2\left(x\right)\right)dx+\left(x^2+2y\right)dy=0$

$\frac{\left(5x^3+8x^2+27x+36\right)}{\left(x^4+9x^2\right)}$

$\lim_{n\to\infty}\left(\frac{\frac{n^4+1}{7n^8+\sqrt[5]{n}}}{\frac{1}{n^{\frac{1}{5}}}}\right)$

$t^2\:-\:13t\:+\:40$