1 -1 5 -1 1 1 -2 3 3 -1 8 1 1 3 -9 7r2-r1,r3-3r1,r4-r11 -1 5 -1 0 2 -7 4 0 2 -7 4 0 4 -14 8r3-r2,r4-2r2, r2*(1/2),r2+r11 0 3/2 1 0 1 -7/2 2 0 0 0 00 0 0 0 \满意请采纳^_^
FF
