Question

For the straight line defined by the points (2,55) and (4,87), determine the slope (m) and y-intercept (b). Do not round the answers.

Answer 1

• m = 16
• b = 23

Explanation:

It is useful to start with the 2-point form of the equation for a line. For points (x1, y1) and (x2, y2), that equation is ...

y = (y2 -y1)/(x2 -x1)(x -x1) + y1

For the given points, the equation is ...

y = (87 -55)/(4 -2)(x -2) + 55

y = 16(x -2) +55

y = 16x +23

Compare this to the slope-intercept form

y = mx + b

and you see that the slope (m) is 16, and the intercept (b) is 23.