You can solve this question using two different methods. One is obviously a hit and trial method in which you keep guessing a number which gives the same amount of total cost. Second is forming two different equations and then solving them using simultaneous methods learnt.
The correct answer is 75 miles. I used the hit and trial method. You can see 20 + 75 * 0.35 = 46.25 and similarly 35 + 75 * 0.15 = 46.25. Hence the same cost.
The expanded form is: 800,000,000+70,000,000+ 6,000,000
g(x) = x^2 + 1(3x - 5)
<em><u>Replace all x's with 4.</u></em>
g(4) = 4^2 + 1(3 * 4 - 5)
g(4) = 16 + 1(12 - 5)
g(4) = 17(7)
g(4) = 119 (This is your answer.)