This document contains notes from mathematics lessons on representing proportional relationships with equations. It includes examples of setting up proportional relationships between variables like gallons of gas used and miles driven. Students are given practice problems to determine constants of proportionality from tables and graphs, then using the proportional relationships to solve problems algebraically. The document also provides solutions to these practice problems.
12. Module 7.1 Lessons 89.notebook
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September 11, 2015
b. Write the equation that will relate the miles driven to the number
of gallons of gas.
Steps to figure out the equation.
1. Which unit is the dependent variable?
2. Which unit is the independent variable?
3. Find the k.
Constant of Proportionality = k =
4. Plug in the value of k to y = kx.
The constant
x is known as the independent
variable and
y as the dependent variable,.
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September 11, 2015
c. Knowing that there is a half gallon left in the gas tank when the light
comes on, will she make it to the nearest gas station? Explain why or
why not.
Using Arithmetic Using Algebra
d. Using the equation found in part b, determine how far your mother
can travel on 18 gallons of gas. Solve the problem in two ways.
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September 11, 2015
Problem Set S.35
a. Which variable is the dependent variable and why?
b. Is miles driven proportionally related to gallons of gas consumed? If
so what is the equation that relates miles driven to gallons?
c. In any ratio relating gallons and miles driven, will one of the values
always be larger, if so, which one?
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September 11, 2015
Problem Set S.35
d. If the number of gallons is known, can you find the miles driven? Explain
how this value would be calculated.
e. If the number of miles driven is known, can you find the number of
gallons consumed?
f. How many miles could be driven with 18 gallons of gas?