Algebra 2 Common Core

Published by Prentice Hall
ISBN 10: 0133186024
ISBN 13: 978-0-13318-602-4

Chapter 3 - Linear Systems - 3-2 Solving Systems Algebraically - Practice and Problem-Solving Exercises - Page 147: 47

Answer

The solution to this system of equations is $m=4,$ and $n=-3$ or $(4, -3)$.

Work Step by Step

We need to convert the equations so that one variable is the same in both equations, except they have opposite signs. If we add these two equations together, we can eliminate one variable and just deal with one variable instead of two: It might be easier to get rid of the $m$ terms in both equations, so we want to multiply the first equation by $-3$ and the second equation by $2$ to be able to eliminate the $m$ term: $(-3)(2m + 4n) = (-3)(10)$ $ (2)(3m + 5n) = (2)(11)$ Multiply to simplify: $-6m - 12n = -30$ $ 6m + 10n = 22$ Now, we can add the two equations together to come up with one single equation: $(-6m-12n)+(6m+10m)=-30+22\\ -2n = -8$ Divide each side by $-2$ to solve for $n$: $n = 4$ Now that we have the value for $n$, we can plug it into one of the equations to solve for $m$. Let us plug in the value for $n$ into the first equation: $2m + 4(4) = 10$ $2m + 16 = 10$ Now, we subtract $16$ from both sides of the equation to isolate constants to the right side of the equation: $2m = -6$ Divide both sides by $2$ to solve for $m$: $m = -3$ The solution to this system of equations is $m=4,$ and $n=-3$ or $(4, -3)$.
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.