Chapter 3 Linear Systems and Matrices - 3.2 Solve Linear Systems Algebraically - 3.2 Exercises - Skill Practice - Page 165: 54c

$r=1,t=9,s=-\frac{7}{3}$

Let $r=1,t=9$. Then if $(2,-3)$ is a solution (which is a good solution for the first equation), then $1(2)+s(-3)=9\\s=-\frac{7}{3}$ This is not a multiple of the first equation because the constant is the same, but the coefficients are different.