Question

Points (2, 4), (−1, −2) and (3, 6) lie on a line. Write the equation of that line.

Answer 1

The table of points on a line are shown below:

x	2	$-$1	3
y	4	$-$2	6

Here, we can see that the value of y- co-ordinate is the value of x-co-ordinate multiplied by 2.
$$\begin{gathered} \text{That is},2\times 2=4 \\ -1\times 2=-2 \\ \mathrm{and}3\times 2=6. \end{gathered}$$

Therefore, equation of the line is y = 2x.