Elementary Algebra

Published by Cengage Learning
ISBN 10: 1285194055
ISBN 13: 978-1-28519-405-9

Chapter 8 - Coordinate Geometry and Linear Systems - 8.6 - Elimination-by-Addition Method - Problem Set 8.6 - Page 378: 51


6 dollars for cheese pizza and 8 dollars for pepperoni pizza.

Work Step by Step

We call x the cost of cheese pizzas and y the cost of pepperoni pizza. Thus, we obtain: $ 5x +12y =126 $ And $ 9x +20y = 214$ In order to solve this problem, we multiply one or both of the equations by a value that will make one of the variables cancel. We multiply the top equation by -9, and we multiply the bottom equation by 5. Then, we add the two equations to obtain: $-8y = -64 \\ y =8 $ We plug in the given value into the top equation and solve for the other variable: $ 5x + 12(8) = 126 \\ 5x = 30 \\ x =6$
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.