The line equation in slope-intercept form is , where m is the slope and b is the y-intercept.

First find the slope (m).

The slope formula is .

                          (Replace   with 7, 1, 7 and 8)

                          (Subtract: )

                                (Apply additive inverse property: )

since denominator is zero division is not possible so, slope of the line is undefined.

For all y-values x value is same, So, line is a vrtical line passing through the point (7, 1).

Hence the line equation  is .

The equation in slope-intercept form is .