Question

If a line includes the points (8,0) and (20,12). What is its equation in slope-intercept form?

Answer 1

The slope-intercept form:

$y=mx+b$

m - slope

b - y-intercept

The formula of a slope:

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

substitute the coordinates of the points (8, 0) and (20, 12) to the formula:

$m=\dfrac{12-0}{20-8}=\dfrac{12}{12}=1$

y = 1x + b = x + b

Put the coordinates of the point (8, 0) to the equation of a line:

0 = 8 + b      subtract 8 from both sides

-8 = b

Answer: y = x - 8