The equation of a line joining (0, 0) and (1, 1) is:

1. From (0, 0) to (1, 1) the x and y changes are both 1. 2. For any point on the line, the x and y differences from (0, 0) are equal. 3. So for any (x, y) on the line, y = x. 4. Equivalently x − y = 0. 5. The other equations do not pass through both (0, 0) and (1, 1). _Source: SCERT Kerala Std X Mathematics Part-2, Chapter 9-11 (pp 227-246, 2019 ed.)._