求用方程解此题.

1个回答

  • 设上坡路xkm,平路ykm.

    (x/3)+(y/4)=54/60①,(y/4)+(x/5)=42/60②.

    ①×60,得20x+15y=54③,②×60,得15y+12x=42④.

    ③-④,得8x=8,x=1⑤.

    ⑤代入②,得15y+12=42,y=2.

    ∴上坡路1km,平路2km.∴甲乙全程为1+2=3(km).

    答:甲乙全程为3km.