# Lesson 9

Slopes and Equations for All Kinds of Lines

### Problem 1

For each graph, calculate the slope of the line.

### Problem 2

Match each pair of points to the slope of the line that joins them.

### Problem 3

Draw a line with the given slope through the given point. What other point lies on that line?

1. Point A, slope = $$\text-3$$
2. Point A, slope = $$\frac {\text{-}1}{4}$$
3. Point C, slope = $$\frac {\text{-}1}{2}$$
4. Point E, slope = $$\frac {\text{-}2}{3}$$

### Problem 4

Suppose you wanted to graph the equation $$y=\text-4x-1$$.

1. Describe the steps you would take to draw the graph.

2. How would you check that the graph you drew is correct?

### Problem 5

Write an equation for each line.

### Problem 6

A publisher wants to figure out how thick their new book will be. The book has a front cover and a back cover, each of which have a thickness of $$\frac{1}{4}$$ of an inch. They have a choice of which type of paper to print the book on.

1. Bond paper has a thickness of $$\frac{1}{4}$$ inch per one hundred pages. Write an equation for the width of the book, $$y$$, if it has $$x$$ hundred pages, printed on bond paper.
2. Ledger paper has a thickness of $$\frac{2}{5}$$ inch per one hundred pages. Write an equation for the width of the book, $$y$$, if it has $$x$$ hundred pages, printed on ledger paper.
3. If they instead chose front and back covers of thickness $$\frac{1}{3}$$ of an inch, how would this change the equations in the previous two parts?