t≤ 150

150 350(0.25t+20.5)-(0. 19t+2 1.5)= 0.06t- 1 > 0

∴ The cost of the two charging methods is equal, and the value of t is 150 350 Toll: 58+0.25 (x-150) = 0.25t+20.5;

(3) Charge for T > 350 in Formula 2: 88+0.19 (x-350) = 0.19t+21.5.

(2) First, judge that the two formulas are equal, and the process of establishing T-range is the answer.

(3) The comparison between the two kinds of interval charges is the answer.