Theory:

Let's see how to create tables and how to write linear equations using two variables for patterns.
 
Reference_1.png
 
Look at the above pattern and form a table.
 
Let us take, \(x\) be the number of steps (or) number of columns and \(y\) be the number of square boxes within every column.
 
Number of steps \((x)\) \(1\) \(2\)  \(3\) \(4\)   …
Number of square boxes \((y)\) \(2\)  \(4\) \(6\)   \(8\) …
 
Now, find the relationship between the two variables \(x\) and \(y\).
 
For \(x = 1\), \(y = 2\)
 
\(y\) can be rewritten as \(y = 2 \times 1\)
 
As \(x = 1\), we can write \(y = 2 \times x = 2x\) - - - - - - - (I)
 
For \(x = 2\), \(y = 4\)
 
\(y\) can be rewritten as \(y = 2 \times 2\)
 
As \(x = 2\), we can write \(y = 2 \times x = 2x\) - - - - - - - (II)
 
For \(x = 3\), \(y = 6\)
 
\(y\) can be rewritten as \(y = 2 \times 3\)
 
As \(x = 3\), we can write \(y = 2 \times x = 2x\) - - - - - - - (III)
 
For \(x = 4\), \(y = 2\)
 
\(y\) can be rewritten as \(y = 2 \times 4\)
 
As \(x = 4\), we can write \(y = 2 \times x = 2x\) - - - - - - - (IV)
 
From equation (I), (II), (III) and (IV):
 
We can generalise the relation as \(y = 2 \times x\) or \(y = 2x\).