Use the slope-intercept form to write an equation of the line with the given properties. S...

Use the slope-intercept form to write an equation of the line with the given properties. See Example.

EXAMPLE Use the slope-intercept form to write an equation of the line that has a slope of 4 and passes through (5, 9).

Strategy We will substitute 4 for m, 5 for x, and 9 for y in the slope-intercept form y = mx + b and solve for b.

WHY The directions indicate to use the slope-intercept form to find the equation of the line.

Solution

Because m = 4 and b = -11, the equation is y = 4x- 11.

When an equation of a line is written in slope-intercept form, the coefficient of the x-term is the line's slope and the constant term gives the y-coordinate of the y-intercept.

passing through (6, 8) and (2,10)