$a^2.b^4.c^2.a^8.c^8.b^3.a^3$

$2x\frac{dy}{dx}\:-lnx^2\:=0;\:y\left(1\right)=2$

$\lim_{x\to0}\left(\frac{e^{13x}-e^{3x}}{10x}\right)$

$4a-3b-5b+2a+4b-6a-4b$

$\int\frac{1}{x\left(2x-1\right)}dx$

$\sin\left(x+y\right)-\sin\left(x-y\right)=2\sin\left(y\right)\cos\left(x\right)$

$-2ycosxdx\:=\:3senxdy$