求解方程组2x+3y=13,3x-5y=-9 x=y-z=4 2x-y=3z=-3 3x-y-2z=3
问题描述:
求解方程组2x+3y=13,3x-5y=-9 x=y-z=4 2x-y=3z=-3 3x-y-2z=3
答
2x+3y=13,(1)3x-5y=-9 (2)解,得:由(1)*5+(2)*3,得:10x+15y+9x-15y==65-2719x==38x==2把x带入(2)得:6-5y==-95y==15y==3x+y-z=4 (1)2x-y+3z=-3 (2)3x-y-2z=3 (3)解,得:由(1)+(2)得3x+2z==1 (4)...