Final answer:
It doesn't matter which point you choose when writing the equation in point-slope form because a line has a constant slope between any two points. Therefore, any point would lead to an equivalent equation with the same slope and y-intercept representation.
Step-by-step explanation:
The reason why it does not matter which point you choose when writing the equation of a line in point-slope form is that a line has a constant slope between any two points on it. Hence, choosing either point A or point B to write the point-slope form of the equation will result in an equivalent equation. This is because the slope of the line, calculated as the change in the vertical axis divided by the change in the horizontal axis, will be the same regardless of which point is chosen.
The y-intercept is the point where the line crosses the y-axis, and the slope is the measure of how steep a line is, which could be positive, negative, zero (for horizontal lines), or undefined (for vertical lines). The point-slope form of a line equation is represented as y - y1 = m(x - x1), where (x1, y1) is a point on the line and m is the slope. Both points lie on the same straight line; thus, their slope with respect to any other point on the line, such as the y-intercept, is identical.