Page 376 - Algebra 1

L E S S O N Identifying, Writing, and Graphing
56
Direct Variation
Warm Up
New Concepts
1. Vocabulary In the expression 3x + 7, the coefficient is . (2)
Solve for y.
2. 3x + 2y = 8 3. 5y = 3x
(29) (29)
4. Find the range of the function y = _3 x for the domain {0, 5, 10}.
(25) 5
Exploration Using Direct Variation
To make 1 pitcher of lemonade, 5 lemons are used.
a. Model Copy and complete the table to show how many lemons are needed to make each number of pitchers of lemonade.
Pitchers of Lemonade (x)
Lemons (y)
Ratio of Lemons to Pitchers
1
5
_5 = 5 1
2
3
4
5
Math Reasoning
Analyze Find the slope of the graph and compare it to the ratio.
Online Connection www.SaxonMathResources.com
b. Formulate Write a function rule for determining the number of lemons needed.
c. How does the coefficient of x in the function rule compare to the ratio of lemons to pitchers?
d. Graph the function.
e. How many lemons are needed for 8 pitchers?
f. How many pitchers can be made from 47 lemons?
Lesson 56 361