按照顺序,将上面三个式子称为1,2,3
由1式得:S=vt,代入3式:
(vt-100)/v + 100/(0.8v) = t + 1/3
化简:
t - 100/v + 125/v = t + 1/3
两边消去t得:
25/v = 1/3
v = 75
S=vt,代入2式:
2 + (vt - 2v)/0.8v = t + 1
化简得:2 + 1.25t - 2.5 = t + 1
0.25t = 1.5
t = 6
S= vt = 75 * 6 = 450
因此:S=450,v=75,t=6