Chapter 4 - Section 4.3 - Solving Systems of Linear Equations by Addition - Exercise Set - Page 308: 34

$(-\frac{1}{3},-3)$

$-9(x+3)=8y$ $3x-3y=8$ Expand and arrange the first equation. $-9x-27=8y$ $-9x-8y=27$ $-9x-8y=27$ $3x-3y=8$ Multiply the second equation by 3. $-9x-8y=27$ $9x-9y=24$ Add both equations. $-17y=51$ $y=-3$ Solve for $x$. $3x-3y=8$ $3x-3(-3)=8$ $3x+9=8$ $3x=-1$ $x=-\frac{1}{3}$ $x=-\frac{1}{3}; y=-3$ $(-\frac{1}{3},-3)$