设轮船在静水中速度为x km/h.由题知：t=s/v则46/(x+3)+34/(x-3)=80/x化简得：（80x-36）/(x^2-9)=80/x36x=720得x=202.化简2(x+1)^2/x^2 - 3(x+1)/x +1 =0{2(x+1)^2 - 3(x+1)x +x^2}/x^2 =0 (2x^2+4x+2-3x^2-3x+x^2)/...