# Chapter 4 - Review Exercises - Page 337: 18

{(1,-4)}

#### Work Step by Step

5y-x=-21 5y-5y-x=-5y-21 -x=-5y-21 -1(-x)=-1(-5y-21) x=5y+21 Plug this value for x into the other equation 3x+4y=-13 3(5y+21)+4y=-13 15y+63+4y=-13 15y+4y+63=-13 19y+63=-13 19y+63-63=-13-63 19y=-76 y=-$\frac{76}{19}$ y=-4 Plug this value for y into the first equation to find x. x=5y+21 x=5(-4)+21 x=-20+21 x=1 Therefore the solution is {(1,-4)}

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.