1、（1）y1＝25＋0.4x y2=0.6x(2)当x＜125min时,甲合算；当x=125min时,甲、乙两种一样；当x=125min时,乙合算.2、y1=0.58x y2=0.28x+600(2)当y1=y2=1500时,y1=1500=0.58xx≈2586y2=1500=0.28x+600x≈3214∴选择公路运...