Big Ideas Math - Algebra 1, A Common Core Curriculum

Published by Big Ideas Learning LLC
ISBN 10: 978-1-60840-838-2
ISBN 13: 978-1-60840-838-2

Chapter 5 - Solving Systems of Linear Equations - 5.2 - Solving Systems of Linear Equations by Substitution - Exercises - Page 245: 12

Answer

The solution is $(3,22)$.

Work Step by Step

The given system of equations is $\Rightarrow -5x+3y=51$ ...... (1) $\Rightarrow y=10x-8$ ...... (2) Substitute $10x-8$ for $y$ in equation (1). $\Rightarrow -5x+3(10x-8)=51$ Use distributive property. $\Rightarrow -5x+30x-24=51$ Add like terms. $\Rightarrow 25x-24=51$ Add $24$ to each side. $\Rightarrow 25x-24+24=51+24$ Simplify. $\Rightarrow 25x=75$ Divide each side by $25$. $\Rightarrow \frac{25x}{25}=\frac{75}{25}$ Simplify. $\Rightarrow x=3$ Substitute $3$ for $x$ in equation (2). $\Rightarrow y=10(3)-8$ Simplify. $\Rightarrow y=30-8$ $\Rightarrow y=22$ Check Equation (1) $\Rightarrow -5x+3y=51$ $\Rightarrow -5(3)+3(22)=51$ $\Rightarrow -15+66=51$ $\Rightarrow 51=51$ True. Check Equation (2) $\Rightarrow y=10x-8$ $\Rightarrow 22=10(3)-8$ $\Rightarrow 22=30-8$ $\Rightarrow 22=22$ True. Hence, the solution is $(3,22)$.
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.