Variable

Let (see what let means) a variable be a symbol that represents a literal thing.

I can define what number it represents by saying “it’s equal to this”

Example:

Let

\begin{gather*} x=1 \end{gather*}

Now if I add something to that variable, I’m going to write a double arrow “ $\Rightarrow$ ” on the left of it to show that “Therefore this is true”

Example:

\begin{gather*} x=1\\ \Rightarrow x+1=1+1\\ \Rightarrow x+1=2 \end{gather*}

$\Rightarrow x+5=6$ , as $x=1$ , we’d just put 1 in place of the $x$