若x,y,z满足3x+7y+z=1和4x+10y+z=200,则x+3y分之2000x+2000y+2000z的值为?
问题描述:
若x,y,z满足3x+7y+z=1和4x+10y+z=200,则x+3y分之2000x+2000y+2000z的值为?
答
把3x+7y+z=1看成(1),4x+10y+z=200看成(2),(2)-(1)=x+3y=199.在(2)中可把等式看成x+y+z+3x+9y=200.由上得:x+y+z=-397.代入原式=…=-794000/199