(Ⅱ)minz=y+y2+y3 X1x 0 +9x1+5x2 14 S·t y2+x1+3x2-2x3=2 y3+3x1-2x2+3x3=4 y>0,x>0(i=1,2,3;j=1,2,3) 人造基B=(PP2P3,P)(Ⅱ) min z = y1+ y2+ y3 S － x1 －x2 －x3 = 0 y1 +9x1 +5 x2 = 14 y2 + x1 + 3x2－2x3 = 2 y3 + 3x1－2x2 + 3x3 = 4 yi≥0, xj≥0 ( i = 1, 2, 3; j = 1, 2, 3 ) . 人造基 B = ( P1 , P2 , P3 , P4 )        s t