${\displaystyle 𝑎=𝑏}$ $𝑎=𝑏$ $𝑎=𝑏$ $𝑎=𝑏$ $$\left(\begin{array}{ccc}1& 0& 0\\ 0& 1& 0\\ 0& 0& 1\end{array}\right)=\{\begin{array}{cc}1\hfill & \text{if <math xmlns="http://www.w3.org/1998/Math/MathML"> <mi>𝑎</mi> <mo lspace="0.278em" rspace="0.278em">=</mo> <mi>𝑏</mi> </math>}\hfill \\ 2\hfill & \text{else}\hfill \end{array}$$ $$𝑥=\frac{-𝑏\pm \sqrt{{𝑏}^2-4𝑎𝑐}}{2𝑎}.$$ $$\sum _{𝑎}\underset{\_}{𝑐}\stackrel{.}{𝑏}{𝑐}^{\mathrm{\prime }}$$ $$\begin{array}{}\text{(1)}& 𝑎𝑏𝑐& =𝑑𝑒𝑓& {𝑒}^{\mathrm{i}𝜋}& =-1\text{(2)}& (1+2& =3)& & \text{(3)}& 5& & & \end{array}$$ $\sin (𝑥)-\sin (𝑥+2𝜋)=0$