# MA.912.A.3.9 Slope and Intercepts

## Rationals-Discrete

Section 3-1 Pages 154-155
Section 3-2 Pages 161-163
Section 3-3 Pages 170-171
Section 3-4 Page 180
Section 4-1 Page 216
Section 4-2 Pages 224-226
Section 4-3 Pages 231-233

## What You Need To Know...

Determine the slope, x-intercept, and y-intercept of a line given its graph, its equation, or two points on a line.

1. The benchmark will be assessed using MC (Multiple Choice) and FR (Fill in Respons).
2. Equations of lines may be represented in various forms including slope-intercept, standard, and point-slope.
3. Items may include lines with zero slope or undefined slope.
4. Items may be in real-world or mathematical context.

## Example One

An architect designed an outdoor staircase for a house.  The relationship between the height of the steps and the length of the tread is modeled by the equation 57x   95y = 0.

Which of the following represents the slope of the equation? ## Example Two

An engineer needs to determine the slope between two points on a gondola ride in order to evaluate the power requirements when the gondola is full of passengers.  A coordinate grid has been placed over a diagram between the two points, as shown below.  For estimation purposes, a straight line between the two points can be used to find the slope.

GONDOLA RIDE Assuming the cable runs in a straight line, what is the slope of the line between the two points shown? ## Example Three

Brianna plotted the two points (20, 75) and (45, 150) on a graph.  What is the x-coordinate of the x-intercept of the line that contains these two points? ## Example Four

Samuel graphed the equation shown below. What is the y-intercept of the line?  Finding Intercepts 