Chapter 9 - Section 9.1 - Solving Systems of Linear Equations in Three Variables and Problem Solving - Exercise Set - Page 637: 13

$(-3, -35, -7)$

A: $6x-5z=17$ B: $5x-y+3z=-1$ C: $2x+y=-41$ 3A+5B $3(6x-5z)+5(5x-y+3z)=3*17+5*-1$ $18x-15z+25x-5y+15z=51-5$ $43x-5y=46$ $2x+y=-41$ $43x-5y=46$ $5*(2x+y)+43x-5y=-41*5+46$ $10x+5y+43x-5y=-205+46$ $53x = -159$ $53x/53 = -159/53$ $x=-3$ $6x-5z=17$ $6*-3-5z=17$ $-18-5z=17$ $-5z=35$ $-5z/-5=35/-5$ $z=-7$ $2x+y=-41$ $2*-3+y=-41$ $-6+y=-41$ $y=-35$