# Lesson 4

Tables, Equations, and Graphs of Functions

### Problem 1

The graph and the table show the high temperatures in a city over a 10-day period.

 day temperature (degrees F) 1 2 3 4 5 6 7 8 9 10 60 61 63 61 62 61 60 65 67 63
1. What was the high temperature on Day 7?

2. On which days was the high temperature 61 degrees?

3. Is the high temperature a function of the day? Explain how you know.

4. Is the day a function of the high temperature? Explain how you know.

### Problem 2

The amount Lin’s sister earns at her part-time job is proportional to the number of hours she works. She earns \$9.60 per hour.

1. Write an equation in the form $$y=kx$$ to describe this situation, where $$x$$ represents the hours she works and $$y$$ represents the dollars she earns.

2. Is $$y$$ a function of $$x$$? Explain how you know.

3. Write an equation describing $$x$$ as a function of $$y$$.

### Problem 3

Use the equation $$2m+4s=16$$ to complete the table, then graph the line using $$s$$ as the dependent variable.

 $$m$$ $$s$$ 0 -2 3 0

### Problem 4

Solve the system of equations: $$\begin{cases} y=7x+10 \\ y=\text-4x-23 \\ \end{cases}$$