Question

A line passes through (5,-4) and (-1,-4). Write the equation of the line in slope-intercept form.

Answer 1

Explanation:

The formula of the slope of a line that passes through points (x1, y1) and (x2, y2) is:

$m=\frac{y_1-y_2}{x_1-x_2}$

For this problem the slope is:

$m=\frac{-4-(-4)}{5-(-1)}=\frac{-4+4}{5+1}=\frac{0}{6}=0$

A slope of zero indicates that the line is horizontal. Therefore it is a constant.

The slope-intercept form of the equation of a line is:

$y=mx+b$

Where m is the slope and b is the y-intercept. In this case, the slope is zero so we just have:

$y=b$

b is the y-coordinate of the given points: b = -4

Answer:

y = -4