$\int_3^{2x}\left(t^2-1\right)dt$

$3-x\le4$

$\lim_{x\to0}\left(\frac{\frac{cos}{x}-\frac{sin\left(x\right)}{x^2}}{cos\left(x\right)}\right)$

$1+\frac{sin\left(x\right)}{cos\left(x\right)}=\frac{1}{cos\left(x\right)}$

$dy-2xydx=0$

$\left(3x^{3}-2x-5x+8\right)+\left(6x^{3}-15x+21x^{2}-5\right)$

$\log\left(3x+1\right)-\log\left(x-5\right)=\log\left(x+4\right)$