x+13y+7z=4z=(4-25x-13y)/7=-3x-y+2(2-2x+3y)/7令s=(2-2x+3y)/72x-3y+7s=2x=(2+3y-7s)/2=1+y-3s+(y-s)/2令t=(y-s)/2y=s+2tx=1+y-3s+t=1-2s+3tz=-3x-y+2s=-3+7s-11t任意代入一对整数s和t即可得一组整数解!!欢迎采纳!