$\begin{array}{l}\mathrm{x**2-1=0}\\ \mathrm{>>>}[-1,1]\end{array}$

$\begin{array}{l}\mathrm{x**2-y**2=0}\\ \mathrm{>>>}[-y,y]\end{array}$

$\begin{array}{l}\mathrm{solve(2y-x-1,4y-x-3)}\\ \mathrm{>>>}\{x:1,y:1\}\end{array}$

$\begin{array}{l}\mathrm{f\text{'}\text{'}+9f=0}\\ \mathrm{>>>}f\left(x\right)=C_1*sin(3*x)+C_2*cos(3*x)\end{array}$

$\begin{array}{l}\mathrm{diff(f,x,2)+9f=0}\\ \mathrm{>>>}f\left(x\right)=C_1*sin(3*x)+C_2*cos(3*x)\end{array}$

$\begin{array}{l}\mathrm{1+2f\text{'}(x)/f+3f\text{'}(y)/f=0}\\ \mathrm{>>>}f(x,y)=F(3*x-2*y)*e^{-\frac{2*x}{13}-\frac{3*y}{13}}\end{array}$

$\begin{array}{l}\mathrm{1+2*diff(f,x,1)/f+3*diff(f,y,1)/f=0}\\ \mathrm{>>>}f(x,y)=F(3*x-2*y)*e^{-\frac{2*x}{13}-\frac{3*y}{13}}\end{array}$