For the following exercises, solve each system by Gaussian elimination. 17. 2x-y+32 17 -5x+4y-22=-46 2y+5x=-7 20. 4x+6y 2z = 8 6x+9y-32-12 -2x-3y+2=-4 23. x+y+2=14 2y+32=-14 -16y-242 -112 18.5x-6y+32=50 -x+4y-10 2x - z=10 21. 2x+3y-4x=5 -3x+2y+ -x+5y+32 4 11 24. 5x-3y+4x=-1 -4x+2y-320 -x+5y+7x=-11 19. 2x+3y 6z 1 -4x 6y+12z = -2 - x+2y+5z 10 22. 10x+2y 14z = 8 -x-2y-42--1 -12x-6y+6z=-12 25. x+y+2=0 2x-y+32=0 x-2=0