College Algebra (11th Edition)

Published by Pearson
ISBN 10: 0321671791
ISBN 13: 978-0-32167-179-0

Chapter 5 - Section 5.1 - Systems of Linear Equations - 5.1 Exercises - Page 487: 38

Answer

Infinitely many solutions Solution set $(2+4y,y)$, where $y$ arbitrary

Work Step by Step

Let's note the equations: $$2x-8y =4 ~~~(1) \\ x-4y=2~~~(2)$$ We will apply the Elimination Method. We need to multiply the second equation by $-2$ and by doing so the second equation becomes: $$-2x+8y =-4 ~~~~(3)$$ Next we add equations $(1)$ and $(3)$ in order to eliminate $x$ as follows: $2x-8y-2x+8y=4-4 \\ 0=0 $ As we can notice that both variables are eliminated which implies that the system of equations has infinitely many solutions and we can say that the equations refer to the same line. In order to Isolate $x$ from equation $(2)$, we will solve for $x$ as follows: (Adding $4y$ to both sides of the equation) $$x-4y=2 \implies x-4y+4y=2+4y$$ or, $$x=2+4y$$ Hence, the required solution set with $y$ arbitrary is equivalent to: $$(2+4y,y)$$.
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.