$\int\left(\frac{4x^3}{\left(x^4+1\right)^2}\right)dx$

$\lim_{x\to1}\left(x^{\frac{1}{x^2-1}}\right)$

$( x ) - ( 2 x + 1 ) ^ { 4 }$

$2x+5x-x$

$440\cdot60$

$\left(x\cdot y+y\right)\left(y\cdot x+x\right)$

$\left(\frac{1}{4}x^4\frac{5}{2}x^3+1\right)+\left(\frac{1}{7}x^2+\frac{3}{2}x-\frac{3}{4}\right)+\left(\frac{2}{3}x^4+3x^3-2x^2-\frac{1}{5}x-5\right)$