没有技巧,就是死算。y=(ax+b)e^xy'=ae^x +(ax+b)e^x=(ax+a+b)e^xy''=ae^x+(ax+a+b)e^x=(ax+2a+b)e^xy''-y'-2y=e^x(ax+2a+b)e^x - (ax+a+b)e^x -2(ax+b)e^x=(2x+1)e^xax+2a+b-ax-a-b-2ax-2b=2x+1-2ax+(a-2b)=2x-1所以-2a=2a-2b=1得a=-1,b=-1