济南与北京两地相距480千米,乘坐高铁列车比乘坐普通快车能提前4小时到达.已知高铁列车的平均行驶速度是普通快车的3倍,求高铁列车的平均行驶速度.
济南与北京两地相距480千米,乘坐高铁列车比乘坐普通快车能提前4小时到达.已知高铁列车的平均行驶速度是普通快车的3倍,求高铁列车的平均行驶速度.
解:设普通快车的速度为xkm/h,由题意得:·················································· 1分
·································································································· 3分
=4············································································································ 4分
x=80················································································································ 5分
经检验x=80是原分式方程的解········································································ 6分
3x=3×80=240 ·································································································· 7分
答:高铁列车的平均行驶速度是240km/h.····················································· 8分