Algebra-1

To determine which pair of points would yield a line with an undefined slope, we use the slope formula for two points  and , which is .

A line has an undefined slope when the denominator of the slope formula, , is equal to . That means the -coordinates of the two points must be the same.

Let's analyze each pair of points:

A:  and

For these points, , , , .

The slope .

Since division by zero is undefined, the line passing through these points has an undefined slope.

B:  and

Here, , , , .

The slope

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